Update common's reference

Dimitar Kerezov · Dimitar Kerezov · commit 1d8e97806e6c · 2015-09-04T15:15:43.000+03:00
diff --git a/lib/common b/lib/common
@@ -1 +1 @@
-Subproject commit a3e24299c4763af1f7d2c2307cf4763237034a72
+Subproject commit 620c7b215e794d3daefc1848df8ec2d5f9455249
