fix comments in api proto

Author: FZambia

internal/apiproto/api.pb.go

@@ -845,11 +845,11 @@ message PushLimitStrategy {
 message PushTimeLimitStrategy {
     string send_after_time = 1;  // HH:MM:SS
     string send_before_time = 2; // HH:MM:SS
-    bool no_tz_send_now = 3; // If device timezone is not set - send push now.
+    bool no_tz_send_now = 3; // If device timezone is not set - send push now, by default will be dropped.
 }
 
 message PushRateLimitStrategy {
-    string key = 1; // key for rate limit policy, supports variables (user_id, device_id).
+    string key = 1; // optional key for rate limit policy, supports variables.
     repeated RateLimitPolicy policies = 2;
     bool drop_if_rate_limited = 3;
 }