QMakeVersion: Fix QMakeVersion::equals

Broke in 8e171e0be0 just before 2.3.0

Change-Id: Ic4f4fe1d904c8a3146962e4276ae7e7bf4ed8895
Reviewed-by: Tobias Hunger <tobias.hunger@theqtcompany.com>

src/plugins/qtsupport/baseqtversion.cpp

@@ -659,6 +659,8 @@ QList<Abi> BaseQtVersion::qtAbis() const
 
 bool BaseQtVersion::equals(BaseQtVersion *other)
 {
+    if (m_qmakeCommand != other->m_qmakeCommand)
+        return false;
     if (type() != other->type())
         return false;
     if (uniqueId() != other->uniqueId())