Fix :list* source links.

common/locale/en-US/messages.properties

@@ -175,7 +175,7 @@ io.callingShell-1 = Calling shell to execute: %S
 io.cantCreateTempFile = Couldn't create temporary file
 io.cantEncode = Input contains characters not valid in the current file encoding
 io.commandFailed = E472: Command failed
-io.definedAt = Defined at %S
+io.definedAt = Defined at
 io.downloadFinished-2 = Download of %S to %S finished
 io.eNotDir = Not a directory
 io.exists = File exists (add ! to override)