ProjectNodes: Be less enthusiastic about compression opportunities

Do not compress foldernodes that differ on their type. This makes it
possible to use FolderNode::compress() in one more place in CMake.

Change-Id: I4721d5d12e3032ee70a1c3d9e87df49d59751f04
Reviewed-by: hjk <hjk@qt.io>

src/plugins/cmakeprojectmanager/servermodereader.cpp

@@ -538,6 +538,7 @@ void ServerModeReader::addCMakeLists(CMakeProjectNode *root, const QList<FileNod
                          [&cmakeDirs](const Utils::FileName &fp) -> ProjectExplorer::FolderNode * {
         return cmakeDirs.contains(fp) ? new CMakeListsNode(fp) : new FolderNode(fp);
     });
+    root->compress();
 }
 
 static ProjectNode *findCMakeNode(ProjectNode *root, const Utils::FileName &dir)