groupcachepb: add syntax declaration to proto file

bradfitz · bradfitz · commit 7e022f85f59c · 2016-02-11T14:40:41.000-08:00
Required for Google's internal build system.

Change-Id: I7cc7b1ffab9f4405715eeb675df3bf3bea85f107
diff --git a/groupcachepb/groupcache.proto b/groupcachepb/groupcache.proto
@@ -14,6 +14,8 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
+syntax = "proto2";
+
 package groupcachepb;
 
 message GetRequest {
