Add missing #else for a zero entry in an index mapping

Follow-up to commit dff3843d98.
Noticed during branch-merge conflict resolution.

Change-Id: I9a0ed11853c00f0d260d2fbd5f909ea2a65fd346
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/kernel/qvariant.cpp

@@ -2471,6 +2471,8 @@ static const ushort mapIdFromQt3ToCurrent[MapFromThreeCount] =
     QMetaType::QBitArray,
 #if QT_CONFIG(shortcut)
     QMetaType::QKeySequence,
+#else
+    0, // QKeySequence
 #endif
     QMetaType::QPen,
     QMetaType::LongLong,