adjust heading

(as it applies to both graceful and forced lock attempts)

src/main/resources/i18n/strings.properties

@@ -118,7 +118,7 @@ unlock.error.invalidMountPoint.existing=Mount point "%s" already exists or paren
 
 # Lock
 ## Force
-lock.forced.heading=Graceful lock failed
+lock.forced.heading=Lock failed
 lock.forced.message=Locking "%s" was blocked by pending operations or open files. You can force lock this vault, however interrupting I/O may result in the loss of unsaved data.
 lock.forced.retryBtn=Retry
 lock.forced.forceBtn=Force Lock