add strings

iOSClient/Supporting Files/en.lproj/Localizable.strings

@@ -140,6 +140,7 @@
 "_attention_"               = "Attention";
 "_recent_"                  = "Recent";
 "_view_in_folder_"          = "View in folder";
+"_leave_share_"             = "Leave this share";
 
 // App