Unhandled exception (1e40eceb)

Zeus version:
`1.5.2.21b875`

Firefox version:
`(60, 8)`

Geckodriver version:
`geckodriver-v0.19.0-linux64.tar.gz`

Error info:
```Traceback (most recent call last):
File "/home/tools/dorks/zeus/zeus-scanner/var/search/selenium_search.py", line 268, in parse_search_results
tor=tor, batch=batch, xforward=forward_for
File "/home/tools/dorks/zeus/zeus-scanner/var/search/selenium_search.py", line 82, in get_urls
browser = var.search.SetBrowser(agent=user_agent, proxy=proxy, tor=tor, xforward=xforward).set_browser()
File "/home/tools/dorks/zeus/zeus-scanner/var/search/__init__.py", line 148, in set_browser
executable_path=whichcraft.which("geckodriver"))
File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/firefox/webdriver.py", line 144, in __init__
self.service.start()
File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/common/service.py", line 93, in start
(os.path.basename(self.path), self.start_error_message, str(e)))
File "/usr/lib/python2.7/posixpath.py", line 114, in basename
i = p.rfind('/') + 1
AttributeError: 'NoneType' object has no attribute 'rfind'
```

Running details:
`Linux-5.2.0-kali3-amd64-x86_64-with-Kali-kali-rolling-kali-rolling`

Commands used:
`zeus.py -d inurl:index.php?option=com_realestatemanager --links 50`

Log file info:
```2019-10-16 15:07:43,055;zeus-log;INFO;log file being saved to '/home/tools/dorks/zeus/zeus-scanner/log/zeus-log-29.log'
2019-10-16 15:07:43,055;zeus-log;INFO;using default search engine
2019-10-16 15:07:43,055;zeus-log;INFO;starting dork scan with query 'inurl:index.php?option=com_realestatemanager'
2019-10-16 15:07:43,056;zeus-log;WARNING;will not parse webcache URL's (to parse webcache pass -W)
2019-10-16 15:07:43,056;zeus-log;WARNING;only pulling URLs with GET(query) parameters (to pull all URL's pass -E)
2019-10-16 15:07:43,056;zeus-log;INFO;attempting to gather query URL
2019-10-16 15:07:43,056;zeus-log;INFO;setting up virtual display to hide the browser
2019-10-16 15:07:43,177;zeus-log;INFO;setting the browser
2019-10-16 15:07:43,190;zeus-log;ERROR;selenium_search.pyc failed to gather the URL from search engine, caught exception ''NoneType' object has no attribute 'rfind'' exception has been logged to current log file
Traceback (most recent call last):
File "/home/tools/dorks/zeus/zeus-scanner/var/search/selenium_search.py", line 268, in parse_search_results
tor=tor, batch=batch, xforward=forward_for
File "/home/tools/dorks/zeus/zeus-scanner/var/search/selenium_search.py", line 82, in get_urls
browser = var.search.SetBrowser(agent=user_agent, proxy=proxy, tor=tor, xforward=xforward).set_browser()
File "/home/tools/dorks/zeus/zeus-scanner/var/search/__init__.py", line 148, in set_browser
executable_path=whichcraft.which("geckodriver"))
File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/firefox/webdriver.py", line 144, in __init__
self.service.start()
File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/common/service.py", line 93, in start
(os.path.basename(self.path), self.start_error_message, str(e)))
File "/usr/lib/python2.7/posixpath.py", line 114, in basename
i = p.rfind('/') + 1
AttributeError: 'NoneType' object has no attribute 'rfind'

2019-10-16 15:07:54,395;zeus-log;INFO;Zeus got an unexpected error and will automatically create an issue for this error, please wait
2019-10-16 15:07:54,396;zeus-log;INFO;getting authorization
2019-10-16 15:07:54,396;zeus-log;INFO;extracting traceback from log file
2019-10-16 15:07:54,397;zeus-log;INFO;attempting to get firefox browser version
```

Start with var/search/__init__.py at set_browser, especially the geckodriver lookup on line 148, then follow the call from var/search/selenium_search.py through get_urls. Reproduce the reported Zeus command with the listed Firefox, geckodriver, and Python versions; done means the browser setup no longer produces the reported NoneType traceback when the driver cannot be resolved.

Written by the indexing model from the issue text.