QmlJS indenter: Only auto-reindent if indent was unchanged.

This change in how electric characters are handled has gone into the
C++ indenter a while ago and works well there. It means Creator is less
likely to annoyingly change the indent on lines where the
indentation whas changed manually.
It is still possible to trigger a reindent manually.

Reviewed-by: Erik Verbruggen

src/libs/qmljs/qmljscodeformatter.h

@@ -66,6 +66,7 @@ public:
     void updateLineStateChange(const QTextBlock &block);
 
     int indentFor(const QTextBlock &block);
+    int indentForNewLineAfter(const QTextBlock &block);
 
     void setTabSize(int tabSize);