Remove QmLJSDelta class

The class was only used for the Apply on Save functionality in the
QML Debugger, which got nuked in 3bf81efbe7.

Change-Id: I1842cc07d61fe84f8da23210ebac04dd4d567fce
Reviewed-by: Marco Benelli <marco.benelli@theqtcompany.com>
Reviewed-by: hjk <hjk@theqtcompany.com>

src/libs/qmljs/qmljs.qbs

@@ -30,7 +30,6 @@ QtcLibrary {
             "qmljscompletioncontextfinder.cpp", "qmljscompletioncontextfinder.h",
             "qmljsconstants.h",
             "qmljscontext.cpp", "qmljscontext.h",
-            "qmljsdelta.cpp", "qmljsdelta.h",
             "qmljsdescribevalue.cpp", "qmljsdescribevalue.h",
             "qmljsdocument.cpp", "qmljsdocument.h",
             "qmljsevaluate.cpp", "qmljsevaluate.h",