Fix shell script syntax errors

Fixes #6956

Makefile

@@ -358,7 +358,7 @@ install-linux-scripts:
 	@echo "#!/bin/sh" > openra
 	@echo 'cd "$(gameinstalldir)"' >> openra
 	@echo 'mono OpenRA.Game.exe "$$@"' >> openra
-	@echo 'if [ $$? != 0 && $$? != 1 ]' >> openra
+	@echo 'if [ $$? != 0 -a $$? != 1 ]' >> openra
 	@echo 'then' >> openra
 	@echo 'ZENITY=`which zenity` || echo "OpenRA needs zenity installed to display a graphical error dialog. See ~/.openra. for log files."' >> openra
 	@echo '$$ZENITY --question --title "OpenRA" --text "OpenRA has encountered a fatal error.\nLog Files are available in ~/.openra." --ok-label "Quit" --cancel-label "View FAQ" || xdg-open https://github.com/OpenRA/OpenRA/wiki/FAQ' >> openra

launch-game.sh

@@ -1,7 +1,7 @@
 #!/bin/sh
 # launch script (executed by Desura)
 mono OpenRA.Game.exe Server.Dedicated=False Server.DedicatedLoop=False "$@"
-if [ $? != 0  && $? != 1 ]
+if [ $? != 0 -a $? != 1 ]
 then
 	ZENITY=`which zenity` || echo "OpenRA needs zenity installed to display a graphical error dialog. See ~/.openra. for log files."
 	$ZENITY --question --title "OpenRA" --text "OpenRA has encountered a fatal error.\nLog Files are available in ~/.openra." --ok-label "Quit" --cancel-label "View FAQ" || xdg-open https://github.com/OpenRA/OpenRA/wiki/FAQ

packaging/osx/template.app/Contents/MacOS/OpenRA

@@ -42,7 +42,7 @@ fi
 cd "$RESOURCES" && FONTCONFIG_PATH="." $MONO_BIN --debug OpenRA.Game.exe Graphics.Renderer=Sdl2
 
 # Display an error dialog on game crash
-if [ $? != 0 && $? != 1 ]
+if [ $? != 0 -a $? != 1 ]
 then
 	osascript \
 	-e "set logsPath to ((path to application support folder from user domain) as text) & \"OpenRA:Logs:\"" \