[BUG] Crash due to "syntax error: operand expected (error token is "/")" when CPU usage high (~90%)

**Describe the bug**

Crashes on OSX when CPU usage is high.

Checking the `$HOME/.config/bashtop/error.log`:

```
New instance of bashtop version: 0.9.25 Pid: 86837
-bash: ((: Pid: Program: Arguments:Threads: User: Mem% Cpu%: syntax error in expression (error token is ": Program: Arguments:Threads: User: Mem% Cpu%")
-bash: ((: Pid: Program: Arguments:Threads: User: Mem% Cpu%: syntax error in expression (error token is ": Program: Arguments:Threads: User: Mem% Cpu%")
-bash: ((: /Library: syntax error: operand expected (error token is "/Library")
-bash: ((: /Library: syntax error: operand expected (error token is "/Library")
-bash: /: syntax error: operand expected (error token is "/")
[1]+ Done coproc pycoproc ( python3 ${pywrapper} )
```

**To Reproduce**

Same as the last issue I posted, I'll just copy that info here:

Installation of depedencies was exactly as under the README section `Dependencies installation OSX`

Then:

`git clone https://github.com/aristocratos/bashtop`
`cd bashtop`
`source bashtop`

**Expected behavior**

Bashtop should not crash.

**Screenshots**

N/a

**Info (please complete the following information):**
- Bashtop version: 0.9.25
- (OSX/FreeBSD) Os release version: Catalina 10.15.4
- Terminal used: iTerm 3.3.12
- Font used: Ubuntu Mono
- Bash version, "bash --version" (version 4.4 or above is required): 5.0.17(1)-release (x86_64-apple-darwin19.4.0)
- Locales: "en_US.UTF-8"

**Additional context**

N/a, error.log is already given above