Add _create_folder_

iOSClient/en.lproj/Localizable.strings

@@ -53,6 +53,7 @@
 "_overwrite_"               = "Overwrite";
 "_transfers_in_queue_"      = "Tranfers in progress, please wait ...";
 "_too_errors_automatic_all_"= "Too many errors, go to Control Center to verify the problem";
+"_create_folder_"           = "Create folder";
 
 // App