Fixed issue with commented-out user_pref lines

It ended up being a mixture of the previous commit and the fix. It writes a temporary file on the go that only holds preferences, and generates the target file at once at the end. It's slower than before, but it works.

updater.bat

@@ -207,8 +207,8 @@ EXIT /B
 
 REM ###### Merge function ######
 :merge
-DEL /F %2 2>nul
 SETLOCAL disabledelayedexpansion
+(
 	FOR /F "tokens=1,* delims=]" %%G IN ('find /n /v "" ^< "%~1"') DO (
 		SET "_pref=%%H"
 		SETLOCAL enabledelayedexpansion
@@ -219,7 +219,7 @@ FOR /F "tokens=1,* delims=]" %%G IN ('find /n /v "" ^< "%~1"') DO (
 					SET "_pref=%%S"
 				)
 				SET _pref=!_pref:"=""!
-			FIND /I "!_pref!" %~2 >nul 2>&1
+				FIND /I "!_pref!" updatertempfile1 >nul 2>&1
 				IF ERRORLEVEL 1 (
 					FOR /F "tokens=* delims=" %%X IN ('FIND /I "!_pref!" %~1') DO (
 						SET "_temp=%%X"
@@ -228,17 +228,19 @@ FOR /F "tokens=1,* delims=]" %%G IN ('find /n /v "" ^< "%~1"') DO (
 							SET "_pref=%%X"
 						)
 					)
-				ECHO(!_pref!>>%~2
+					ECHO(!_pref!
+					ECHO(!_pref!>>updatertempfile1
 				)
 			) ELSE (
-			ECHO(!_pref!>>%~2
+				ECHO(!_pref!
 			)
 		) ELSE (
-		ECHO(!_pref!>>%~2
+			ECHO(!_pref!
 		)
 		ENDLOCAL
 	)
+)>%~2
 ENDLOCAL
-DEL /F %1 >nul
+DEL /F %1 updatertempfile1 >nul
 GOTO :EOF
 REM ############################