macOS: Do not switch to the dark theme

If the program/graphics library does not support it properly.
It is better to ignore the dark theme, which create an unreadable/unusable program,
and always show the light theme, which is workable.

Maybe the dark macOS theme will be fixed in the future LCL version.

See issue GerryFerdinandus#49
[skip ci]

Author: GerryFerdinandus

enduser/macos/app/trackereditor.app/Contents/Info.plist

@@ -43,5 +43,7 @@
   <string>iconfile</string>
   <key>NSHighResolutionCapable</key>
   <true/>
+  <key>NSRequiresAquaSystemAppearance</key>
+  <string>YES</string>
 </dict>
 </plist>