vckpg_install.bat: only clone vcpkg when not available already

When developing locally, folks might want to run vcpkg_install.bat multiple times. When the vcpkg folder is already present, cloning it will obviously fail. We would probably prefer to only clone it when it's not already present.

Signed-off-by: Dennis Ameling <dennis@dennisameling.com>

Author: dennisameling

compat/vcbuild/vcpkg_install.bat

@@ -49,9 +49,11 @@ REM ================================================================
 	echo "***"
 	EXIT /B 1 )
 
-	echo Fetching vcpkg in %cwd%vcpkg
-	git.exe clone https://github.com/Microsoft/vcpkg vcpkg
-	IF ERRORLEVEL 1 ( EXIT /B 1 )
+	IF NOT EXIST vcpkg (
+		echo Fetching vcpkg in %cwd%vcpkg
+		git.exe clone https://github.com/Microsoft/vcpkg vcpkg
+		IF ERRORLEVEL 1 ( EXIT /B 1 )
+	)
 
 	cd vcpkg
 	echo Building vcpkg