[BUG] plotfiles not available for farming when a mapped drive is missing

[LoudSyncro]

Describe the bug

When a mapped network drive is listed in config.yaml, but it is not available during chia startup, then no plots (including local plot files) are available to chia for farming.

This affects GUI and CLI.

To Reproduce Steps to reproduce the behavior:

1. Add fake network drive to config.yaml (e.g. \192.168.178.95\E\chia)
2. Shutdown Chia

For GUI:

1. Start Chia GUI
2. A popup with "22" appears
3. check for plots in GUI: No plots are shown at all

For CLI:

1. start Chia: ./chia start farmer
2. wait for services being started
3. Do: ./chia plots show
4. See error message: [2360] Failed to execute script chia

   
   Directories where plots are being searched for:
   Note that subdirectories must be added manually
   Add with 'chia plots add -d [dir]' and remove with 'chia plots remove -d [dir]' Scan and check plots with 'chia plots check'

Traceback (most recent call last): File "src\cmds\chia.py", line 80, in File "src\cmds\chia.py", line 76, in main File "click\core.py", line 829, in call File "click\core.py", line 782, in main File "click\core.py", line 1259, in invoke File "click\core.py", line 1259, in invoke File "click\core.py", line 1066, in invoke File "click\core.py", line 610, in invoke File "click\decorators.py", line 21, in new_func File "src\cmds\plots.py", line 189, in show_cmd File "src\cmds\plots.py", line 25, in show_plots File "src\plotting\plot_tools.py", line 116, in get_plot_directories File "src\plotting\plot_tools.py", line 116, in File "pathlib.py", line 1166, in resolve File "pathlib.py", line 205, in resolve OSError: [WinError 1326] Username or password wrong: '\\192.168.178.95\E\chia' [2360] Failed to execute script chia

**Expected behavior**
1) Proper error handling of Error [2360] / [WinError 1326]  in GUI and CLI, so that a missing network drive cannot break the chia script.
2) Furthermore a meaningfull error / info message to the user would about a missing (network)drive out of the config.yaml makes sense.

**Screenshots**
![2021-04-08 07_20_49-Chia Blockchain](https://user-images.githubusercontent.com/82137080/113978604-6d119900-9844-11eb-82a5-d3d4e3868bc1.png)
![2021-04-08 07_52_20-Administrator_ Windows PowerShell](https://user-images.githubusercontent.com/82137080/113978622-713db680-9844-11eb-8e74-e3100b23a727.png)

**Desktop (please complete the following information):**

- OS: Win10 Pro
- Chia Version 1.0.3

**Additional context**
Add any other context about the problem here.

[aqk]

Thanks for your bug report. This has been entered in our bug tracker for triage.

[github-actions[bot]]

This issue has been flagged as stale as there has been no activity on it in 14 days. If this issue is still affecting you and in need of review, please update it to keep it open.

[github-actions[bot]]

This issue was automatically closed because it has been flagged as stale and subsequently passed 7 days with no further activity.