Fix typo

...which was pointed out in
<https://lists.freedesktop.org/archives/libreoffice/2023-January/089867.html>
"Re: Question re the uno-skeletonmaker'-t' CLI qualifier"

Change-Id: I5f03de657bc93dace104bdd307e8f6938742b61b
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/146126
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

unodevtools/source/skeletonmaker/skeletonmaker.cxx

@@ -248,7 +248,7 @@ SAL_IMPLEMENT_MAIN()
 
     if ( types.empty() && options.componenttype != 3) {
         std::cerr
-            << "\nError: no type is specified, use the -T option at least once\n";
+            << "\nError: no type is specified, use the -t option at least once\n";
         printUsageAndExit(programname, version);
         exit(EXIT_FAILURE);
     }