CppTools: Unexport ProjectFileAdder

Change-Id: Icf53019b594a5c45b06f7f1fab0f4bf36e891918
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

src/plugins/cpptools/cppprojects.cpp

@@ -43,6 +43,7 @@
 #include <QTextStream>
 
 using namespace CppTools;
+using namespace CppTools::Internal;
 using namespace ProjectExplorer;
 
 ProjectPart::ProjectPart()