hgtags: delete "release" (step 1 of new release)

R=r
CC=golang-dev
https://golang.org/cl/180118
diff --git a/.hgtags b/.hgtags
index 62db726..00f8dce 100644
--- a/.hgtags
+++ b/.hgtags
@@ -5,4 +5,3 @@
 d1b75410b793309532352a6fb6b44453f052f3f4 release.2009-11-17
 e205103b02e7393d4719df5faac2dac808234d3f release.2009-12-07
 3a47d2e3882bb12129de05382a2c131bb0c00964 release.2009-12-09
-7929874a70aecc714d5fad4ae1529b1352db6d70 release