Fix tab vs space

Signed-off-by: Derek Nola <[email protected]>

cmd/backport/main.go

@@ -25,7 +25,7 @@ Options:
     -r repo              repository that should be used
     -i issue id          original issue id
     -b branch(es)        branches issue is being backported to
-	-u user			     user to use assign new issues to
+    -u user			     user to use assign new issues to
 
 Examples: 
     # generate 2 backport issues for k3s issue 1234