q_segmentation: disable delta_q encoding when enabled

The decoder side correctly disabled delta_q but the encoder didn't.

Change-Id: I9f720c678d9e99d723c632095c058eaecd1a639d

av1/encoder/bitstream.c

diff --git a/av1/encoder/bitstream.c b/av1/encoder/bitstream.c
index 8656b28..95d1af7 100644
--- a/av1/encoder/bitstream.c
+++ b/av1/encoder/bitstream.c
@@ -4057,6 +4057,9 @@
         segment_quantizer_active = 1;
       }
     }
+#if CONFIG_Q_SEGMENTATION
+    segment_quantizer_active |= !!seg->q_lvls;
+#endif
     delta_q_allowed = !segment_quantizer_active;
 #endif
 
@@ -4417,6 +4420,9 @@
         segment_quantizer_active = 1;
       }
     }
+#if CONFIG_Q_SEGMENTATION
+    segment_quantizer_active |= !!seg->q_lvls;
+#endif
     delta_q_allowed = !segment_quantizer_active;
 #endif