conf: change default session cookie name

[CI SKIP]

conf/app.ini

@@ -271,7 +271,7 @@ PROVIDER = memory
 ; mysql: go-sql-driver/mysql dsn config string, e.g. `root:password@/session_table`
 PROVIDER_CONFIG = data/sessions
 ; Session cookie name
-COOKIE_NAME = i_like_gogits
+COOKIE_NAME = i_like_gogs
 ; If you use session in https only, default is false
 COOKIE_SECURE = false
 ; Enable set cookie, default is true