Remove duplicate string in CLIText.properties

Bug: 438261
Change-Id: Idd6839465ea36d072b1c4393f5abd2f39da02b62

org.eclipse.jgit.pgm/resources/org/eclipse/jgit/pgm/internal/CLIText.properties

@@ -321,7 +321,6 @@ usage_setTheGitRepositoryToOperateOn=set the git repository to operate on
 usage_show=display one commit
 usage_showRefNamesMatchingCommits=Show ref names matching commits
 usage_showPatch=display patch
-usage_showRefNamesMatchingCommits=Show ref names matching commits
 usage_showNotes=Add this ref to the list of note branches from which notes are displayed
 usage_showTimeInMilliseconds=Show mtime in milliseconds
 usage_squash=Squash commits as if a real merge happened, but do not make a commit or move the HEAD.