Json Wizard: Fix unsetting of attributes

This did trigger all kinds of side-effects, one of them was

Task-number: QTCREATORBUG-14294
Change-Id: If39f827828e9c5a2559bd6b3b5392ac819fbd931
Reviewed-by: Daniel Teske <daniel.teske@theqtcompany.com>

src/plugins/projectexplorer/jsonwizard/jsonwizard.cpp

@@ -162,8 +162,10 @@ bool JsonWizard::boolFromVariant(const QVariant &v, Utils::MacroExpander *expand
 
 void JsonWizard::removeAttributeFromAllFiles(Core::GeneratedFile::Attribute a)
 {
-    for (int i = 0; i < m_files.count(); ++i)
-        m_files[i].file.setAttributes(m_files.at(i).file.attributes() ^ a);
+    for (int i = 0; i < m_files.count(); ++i) {
+        if (m_files.at(i).file.attributes() & a)
+            m_files[i].file.setAttributes(m_files.at(i).file.attributes() ^ a);
+    }
 }
 
 void JsonWizard::accept()