Fix another 10L in QPRD

An entry in subpel_iterations was missing.
I have no idea how QPRD was working at all without this change.

encoder/me.c

@@ -42,6 +42,7 @@ static const int subpel_iterations[][4] =
     {0,0,2,2},
     {0,0,2,2},
     {0,0,4,10},
+    {0,0,4,10},
     {0,0,4,10}};
 
 /* (x-1)%6 */