servenv: reduce default lameduck period

Since most tests don't set lameduck period, a high value will
most likely break them all. So, it's good to set this to something
very small.

go/vt/servenv/run.go

@@ -17,7 +17,7 @@ var (
 	onCloseHooks hooks
 
 	Port           = flag.Int("port", 0, "port for the server")
-	LameduckPeriod = flag.Duration("lameduck-period", 30*time.Second, "how long to keep the server running on SIGTERM before stopping")
+	LameduckPeriod = flag.Duration("lameduck-period", 50*time.Millisecond, "how long to keep the server running on SIGTERM before stopping")
 
 	// filled in when calling Run or RunSecure
 	ListeningURL url.URL

test/queryservice_tests/test_env.py

@@ -326,7 +326,6 @@ class VtoccTestEnv(TestEnv):
       "-db-config-app-uname", 'vt_dba',   # use vt_dba as some tests depend on 'drop'
       "-db-config-app-keyspace", "test_keyspace",
       "-db-config-app-shard", "0",
-      "-lameduck-period", "100ms",
     ]
     if self.memcache:
       memcache = self.mysqldir+"/memcache.sock"

test/tablet.py

@@ -292,8 +292,7 @@ class Tablet(object):
     args = [environment.binary_path('vttablet'),
             '-port', '%s' % (port or self.port),
             '-tablet-path', self.tablet_alias,
-            '-log_dir', environment.vtlogroot,
-            '-lameduck-period', '100ms']
+            '-log_dir', environment.vtlogroot]
     args.extend(environment.topo_server_flags())
     args.extend(utils.binlog_player_protocol_flags)