Do not install example sources when using vc(x)proj

Inside Visual Studio these files (INSTALLS) will end up in deployment.
They do not make sense there and might even cause clashes, which prevent
the project file from being loaded (for example when a qrc file is added
to "Resource files" and "Deployment files")

Change-Id: Ifa68c52a83b2bf3948738c7aa1cf9c56b331dc80
Reviewed-by: Andrew Knight <andrew.knight@intopalo.com>
Reviewed-by: Joerg Bornemann <joerg.bornemann@theqtcompany.com>

mkspecs/features/qt_example_installs.prf

@@ -9,6 +9,8 @@
 # We mean it.
 #
 
+contains(TEMPLATE, "vc.*"): return()
+
 defineTest(addInstallFiles) {
     for(sf, 2) {
         sf = $$relative_path($$sf, $$_PRO_FILE_PWD_)