Don't create a default pid file (#637)

cmd/web.go

@@ -62,7 +62,7 @@ and it takes care of all the other things for you`,
 		},
 		cli.StringFlag{
 			Name:  "pid, P",
-			Value: "custom/run/app.pid",
+			Value: "/var/run/gitea.pid",
 			Usage: "Custom pid file path",
 		},
 	},

modules/setting/setting.go

@@ -515,11 +515,9 @@ please consider changing to GITEA_CUSTOM`)
 		}
 	}
 
-	if len(CustomPID) == 0 {
-		CustomPID = CustomPath + "/run/app.pid"
-	}
-
+	if len(CustomPID) > 0 {
 		createPIDFile(CustomPID)
+	}
 
 	if len(CustomConf) == 0 {
 		CustomConf = CustomPath + "/conf/app.ini"