Double disabling gonv environment creates bad terminal state

[swalkerhppr]

Description

Disabling gonv when it is not active causes an error and sets PS1 to an empty string.

Current behavior
What is happening now?

swalker$ t gonv disable
Running gonv:disable task...
Disabling go environment
-bash: rm: No such file or directory
^C
ls
-bash: ls: No such file or directory
exit 
logout

Expected behavior
What should happen?

It should display a message that an environment is not active and not mess up the terminal.

Impact
How does this bug affect you?

Users must log out and log back in to the terminal session if they disable gonv when an environement isn't active.

[swalkerhppr]

This is actually a bigger issue. This puts btm in a persistant bad state where if you try to run anything, ps1 gets messed up:

sdwalker:~/.task-master$ t +v list
GLOBAL VERBOSE SET
Searching /home/sdwalker/.task-master...
Searching /home/sdwalker...
Tasks file:  in /home/sdwalker
State file: /home/sdwalker/.task-master/state/global.vars
Task master has called itself 0 times
Loading internal functions
Loading bash as task driver
Running list: task...

-bash: rm: No such file or directory
-bash: rm: No such file or directory
-bash: rm: No such file or directory
Found /home/sdwalker/.task-master/state/global.vars.export as a state file export, loaded and removed it

More investigation is necessary for how/why it gets into this state, but to fix it I had to remove the global.vars.export file mentioned above.