[FIX] Use ELECTRON_IS_DEV for dev environments with devtools

[YakoYakoYokuYoku]

When using HGL as an unpackaged Electron application (much like code from Arch or zulip-desktop-electron from AUR) the dev environment is loaded by default and it fails to import electron-devtools-installer if a production build was used. So instead of adding electron-is-dev again let's just add ELECTRON_IS_DEV with a default value of 0. Otherwise, if the value is 1 then the dev environment is loaded as desired.

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Use the following Checklist if you have changed something on the Backend or Frontend:

• [x] Tested the feature and it's working on a current and clean install.
• [x] Tested the main App features and they are still working on a current and clean install. (Login, Install, Play, Uninstall, Move games, etc.)
• [x] Created / Updated Tests (If necessary)
• [x] Created / Updated documentation (If necessary)

[flavioislima]

In theory could work but actually in practice it tries to load localhost with the debug enabled, so if fails

So maybe get back to previous idea :)

[arielj]

closing this, there's no sign from the author since May