Removed QtCreator entries from .gitignore

We don't use QtCreator in the SDL project, and it matches the build-scripts directory

.gitignore

@@ -48,11 +48,6 @@ cmake-build-*
 xcuserdata
 *.xcworkspace
 
-# for QtCreator
-CMakeLists.txt.user
-build*/
-*.pro.user*
-
 # for Visual C++
 .vs
 Debug