Remove QT_CLEAN_NAMESPACE/TQT_CLEAN_NAMESPACE unnecessary define.

Signed-off-by: Michele Calgaro <michele.calgaro@yahoo.it>

acinclude.m4

@@ -1882,7 +1882,7 @@ else
  all_includes="$KDE_INCLUDES $all_includes"
 fi
 
-KDE_DEFAULT_CXXFLAGS="-DQT_CLEAN_NAMESPACE -DQT_NO_ASCII_CAST -DQT_NO_STL -DQT_NO_COMPAT -DQT_NO_TRANSLATION"
+KDE_DEFAULT_CXXFLAGS="-DQT_NO_ASCII_CAST -DQT_NO_STL -DQT_NO_COMPAT -DQT_NO_TRANSLATION"
 
 KDE_LDFLAGS="-L$kde_libraries"
 if test ! "$kde_libraries" = "$x_libraries" && test ! "$kde_libraries" = "$qt_libraries" ; then