Fix error message in pg_verify_checksums

5864d24 has introduced a new error message, and I somewhat managed to
fail adapting the back-patched version correctly with the tool name.

Author: michaelpq

src/bin/pg_verify_checksums/pg_verify_checksums.c

@@ -327,7 +327,7 @@ main(int argc, char *argv[])
 	{
 		fprintf(stderr, _("%s: database cluster is not compatible.\n"),
 				progname);
-		fprintf(stderr, _("The database cluster was initialized with block size %u, but pg_checksums was compiled with block size %u.\n"),
+		fprintf(stderr, _("The database cluster was initialized with block size %u, but pg_verify_checksums was compiled with block size %u.\n"),
 				ControlFile->blcksz, BLCKSZ);
 		exit(1);
 	}