crash on startup

### Step 1: Please describe your environment

* ZeroNet version: 0.6.5
* Operating system: osx
* Web browser: brave
* Tor status: unknown
* Opened port: yes/no
* Special configuration: n/a

### Step 2: Describe the problem:
after deleting my port from the config page (thinking it would use default) i saved and it crashed. now every time i try to open it crashes immediately. tried running in debug mode and it doesn't seem to recognize flags

#### Steps to reproduce:

1. take off tor only mode (in tor)
2. remove port from zeronet config
3. restart

#### Observed Results:

* What happened? This could be a screenshot, a description, log output (you can send log/debug.log file to hello@zeronet.io if necessary), etc.

a log file would be great! where can i find it? `log/debug.log` in what folder?

```

~ $ /Applications/ZeroNet.app/Contents/MacOS/ZeroNet --fileserver_port 15441
- Starting ZeroNet...
usage: ZeroNet [-h] [--verbose] [--debug] [--silent] [--debug_socket]
[--batch] [--config_file path] [--data_dir path]
[--log_dir path] [--log_level {DEBUG,INFO,ERROR}]
[--log_rotate {hourly,daily,weekly,off}]
[--log_rotate_backup_count LOG_ROTATE_BACKUP_COUNT]
[--language language] [--ui_ip ip] [--ui_port port]
[--ui_restrict [ip [ip ...]]] [--ui_host [host [host ...]]]
[--ui_trans_proxy] [--open_browser [browser_name]]
[--homepage address] [--updatesite address]
[--size_limit limit] [--file_size_limit limit]
[--connected_limit connected_limit]
[--global_connected_limit global_connected_limit]
[--workers workers] [--fileserver_ip ip]
[--fileserver_port port] [--fileserver_port_range port]
[--fileserver_ip_type {ipv4,ipv6,dual}]
[--ip_local [ip [ip ...]]] [--ip_external [ip [ip ...]]]
[--disable_udp] [--proxy ip:port] [--bind ip]
[--trackers [protocol://address [protocol://address ...]]]
[--trackers_file path] [--trackers_proxy TRACKERS_PROXY]
[--use_openssl {True,False}] [--disable_db]
[--disable_encryption] [--force_encryption]
[--disable_sslcompression {True,False}] [--keep_ssl_cert]
[--max_files_opened limit] [--stack_size thread_stack_size]
[--use_tempfiles {True,False}]
[--stream_downloads {True,False}]
[--msgpack_purepython {True,False}]
[--fix_float_decimals {True,False}]
[--db_mode {speed,security}]
[--download_optional {manual,auto}]
[--coffeescript_compiler executable_path]
[--tor {disable,enable,always}] [--tor_controller ip:port]
[--tor_proxy ip:port] [--tor_password password]
[--tor_use_bridges] [--tor_hs_limit limit]
[--tor_hs_port limit] [--version] [--end]
{main,siteCreate,siteNeedFile,siteDownload,siteSign,sitePublish,siteVerify,siteCmd,dbRebuild,dbQuery,peerPing,peerGetFile,peerCmd,cryptSign,cryptVerify,cryptGetPrivatekey,getConfig,testConnection,testAnnounce}
...
ZeroNet: error: argument --fileserver_port: expected one argument

```

#### Expected Results:

* What did you expect to happen?

for it not to crash