Remove another spurious assert in skip_sgr

Fixes some tests.

Change-Id: Ice2a9e1a57574a3c4393014263bfd1aedc96e4e4

av1/common/restoration.c

diff --git a/av1/common/restoration.c b/av1/common/restoration.c
index 19890e2..3e6409a 100644
--- a/av1/common/restoration.c
+++ b/av1/common/restoration.c
@@ -748,7 +748,6 @@
 #if CONFIG_SKIP_SGR
 void decode_xq(const int *xqd, int *xq, const sgr_params_type *params) {
   if (params->r0 == 0) {
-    assert(xqd[0] == 0);
     xq[0] = 0;
     xq[1] = (1 << SGRPROJ_PRJ_BITS) - xqd[1];
   } else if (params->r1 == 0) {