Fix typo in mutex documentation

Change "more times that" to "more times than"

Author: OverShifted

doc/classes/Mutex.xml

@@ -35,7 +35,7 @@
 			<description>
 				Unlocks this [Mutex], leaving it to other threads.
 				[b]Note:[/b] If a thread called [method lock] or [method try_lock] multiple times while already having ownership of the mutex, it must also call [method unlock] the same number of times in order to unlock it correctly.
-				[b]Warning:[/b] Calling [method unlock] more times that [method lock] on a given thread, thus ending up trying to unlock a non-locked mutex, is wrong and may causes crashes or deadlocks.
+				[b]Warning:[/b] Calling [method unlock] more times than [method lock] on a given thread, thus ending up trying to unlock a non-locked mutex, is wrong and may causes crashes or deadlocks.
 			</description>
 		</method>
 	</methods>