spelling fix.

Author: kivikakk

lib/ferrum/client.rb

@@ -64,7 +64,7 @@ class Client
     delegate %i[timeout timeout=] => :options
 
     attr_reader :ws_url, :options, :subscriber
-    attr_accessor :on_syncronous_message
+    attr_accessor :on_synchronous_message
     def initialize(ws_url, options)
       @command_id = 0
       @ws_url = ws_url
@@ -96,8 +96,8 @@ def send_message(message, async:)
         raise TimeoutError unless data
 
         error, response = data.values_at("error", "result")
-        if on_syncronous_message
-          on_syncronous_message.call(message:, error:, response:)
+        if on_synchronous_message
+          on_synchronous_message.call(message:, error:, response:)
         end
         raise_browser_error(error) if error
         response