Standardize on {MODID} in template files.

packaging/linux/openra-server.in

@@ -1,4 +1,4 @@
 #!/bin/sh
 cd "{GAME_INSTALL_DIR}"
 
-mono {DEBUG} OpenRA.Server.exe Game.Mod={MOD} "$@"
+mono {DEBUG} OpenRA.Server.exe Game.Mod={MODID} "$@"

packaging/linux/openra.appdata.xml.in

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <component type="desktop">
-  <id>openra-{MOD}.desktop</id>
+  <id>openra-{MODID}.desktop</id>
   <metadata_license>CC0-1.0</metadata_license>
   <project_license>GPL-3.0</project_license>
   <name>OpenRA - {MOD_NAME}</name>

packaging/linux/openra.desktop.in

@@ -5,8 +5,8 @@ Name=OpenRA - {MODNAME}
 GenericName=Real Time Strategy Game
 GenericName[de]=Echtzeit-Strategiespiel
 Comment=Reimagining of early Westwood Games
-Icon=openra-{MOD}
-Exec=openra-{MOD} %U
+Icon=openra-{MODID}
+Exec=openra-{MODID} %U
 Terminal=false
 Categories=Game;StrategyGame;
-MimeType=x-scheme-handler/openra-{MOD}-{TAG};
+MimeType=x-scheme-handler/openra-{MODID}-{TAG};