[calls] call: Allow setting NULL id

[Evangelos Ribeiro Tzaras <devrtz src gnome org>]

commit c36b6d713a845e2b614c8c734866f7912abb45fb
Author: Evangelos Ribeiro Tzaras <devrtz fortysixandtwo eu>
Date:   Wed Feb 16 09:42:01 2022 +0100

    call: Allow setting NULL id
    
    A NULL id will be reported for anonymous callers.

 src/calls-call.c | 1 -
 1 file changed, 1 deletion(-)
---
diff --git a/src/calls-call.c b/src/calls-call.c
index 3165aeb9..5c03cdf3 100644
--- a/src/calls-call.c
+++ b/src/calls-call.c
@@ -344,7 +344,6 @@ calls_call_set_id (CallsCall  *self,
   CallsCallPrivate *priv = calls_call_get_instance_private (self);
 
   g_return_if_fail (CALLS_IS_CALL (self));
-  g_return_if_fail (id);
 
   if (g_strcmp0 (id, priv->id) == 0)
     return;