Fix admin-based Autotools configure check failures

git-svn-id: svn://anonsvn.kde.org/home/kde/branches/trinity/kde-common@1234189 283d02a7-25f6-0310-bc7c-ecb5cbfe19da

admin/acinclude.m4.in

@@ -4956,7 +4956,11 @@ AC_DEFUN([KDE_CHECK_STL],
     AC_LANG_CPLUSPLUS
     ac_save_CXXFLAGS="$CXXFLAGS"
     CXXFLAGS="`echo $CXXFLAGS | sed s/-fno-exceptions//`"
-    CXXFLAGS="$CXXFLAGS -I$qt_includes"
+    if test -z "$PKG_CONFIG"; then
+      CXXFLAGS="$CXXFLAGS"
+    else
+      CXXFLAGS="$CXXFLAGS -I$qt_includes"
+    fi
 
     AC_MSG_CHECKING([if C++ programs can be compiled])
     AC_CACHE_VAL(kde_cv_stl_works,