Subinterfaces cause network to not load

**Describe the bug**

When a sub-interface is defined such as lo:0 all of the network reporting breaks.

**To Reproduce**

sudo ifconfig lo:0 up
start bashtop
check error log
sudo ifconfig lo:0 down
start bashtop

**Expected behavior**

If a network interface is unparsable, simply show as UA, or ignore

**Screenshots**

[If applicable, add screenshots to help explain your problem.]

**Info (please complete the following information):**
- Bashtop version: git master
- (Linux) Linux distribution and version: Mint 19 Tara
- (Linux) Data collection type (/proc or psutil): psutil (proc hangs initialization of entire GUI)
- Psutil version: `python3 -c "import psutil; print(psutil.version_info)"` (version 5.7.0 or above is required):
OS installed 5.4.2 (I know, old version, but 5.7.X not showing as avail for my OS even with pip3)
- (OSX/FreeBSD) Os release version: NA
- Terminal used: mate-terminal
- Font used: Monospace Regular 12
- Bash version, `bash --version` (version 4.4 or above is required): 4.4.20
- Locales: output of `locale -v`
LANG=en_US.UTF-8
LANGUAGE=en_US
LC_CTYPE="en_US.UTF-8"
LC_NUMERIC="en_US.UTF-8"
LC_TIME="en_US.UTF-8"
LC_COLLATE="en_US.UTF-8"
LC_MONETARY="en_US.UTF-8"
LC_MESSAGES="en_US.UTF-8"
LC_PAPER="en_US.UTF-8"
LC_NAME="en_US.UTF-8"
LC_ADDRESS="en_US.UTF-8"
LC_TELEPHONE="en_US.UTF-8"
LC_MEASUREMENT="en_US.UTF-8"
LC_IDENTIFICATION="en_US.UTF-8"
LC_ALL=

**Additional context**

contents of `$HOME/.config/bashtop/error.log`
New instance of bashtop version: 0.9.25 Pid: 32381
PSUTIL ERROR! Command: get_nics()
'lo:0'
12:21:34 PM ERROR: On line 1048
PSUTIL ERROR! Command: get_nics()
'lo:0'
12:22:05 PM ERROR: On line 1048 (MUTED!)
PSUTIL ERROR! Command: get_nics()
'lo:0'
PSUTIL ERROR! Command: get_nics()
'lo:0'

New instance of bashtop version: 0.9.25 Pid: 3124

(enable error-logging in "$HOME/.config/bashtop/bashtop.cfg" if missing)