Ensure conflicting option gets passed to all servers in cluster.

src/syn_netsplits.erl

@@ -60,9 +60,9 @@ start_link() ->
 
 -spec conflicting_mode(kill | {send_message, any()}) -> ok.
 conflicting_mode(kill) ->
-    gen_server:call(?MODULE, {conflicting_mode, kill});
+    gen_server:multi_call(?MODULE, {conflicting_mode, kill});
 conflicting_mode({send_message, Message}) ->
-    gen_server:call(?MODULE, {conflicting_mode, {send_message, Message}}).
+    gen_server:multi_call(?MODULE, {conflicting_mode, {send_message, Message}}).
 
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