Remove last traces of --adduser/--no-adduser in createuser

8ae0d476 marked those options as obsolete back in 2005, with the options
removed from the documentation.  This removes the last references to
both options in the code which were kept around for compatibility
purposes with past commands.

Author: Alexander Lakhin
Discussion: https://postgr.es/m/5da284a2-62d9-e338-88d1-26ee5009d93e@gmail.com

src/bin/scripts/createuser.c

@@ -43,9 +43,6 @@ main(int argc, char *argv[])
 		{"replication", no_argument, NULL, 1},
 		{"no-replication", no_argument, NULL, 2},
 		{"interactive", no_argument, NULL, 3},
-		/* adduser is obsolete, undocumented spelling of superuser */
-		{"adduser", no_argument, NULL, 'a'},
-		{"no-adduser", no_argument, NULL, 'A'},
 		{"connection-limit", required_argument, NULL, 'c'},
 		{"pwprompt", no_argument, NULL, 'P'},
 		{"encrypted", no_argument, NULL, 'E'},
@@ -88,7 +85,7 @@ main(int argc, char *argv[])
 
 	handle_help_version_opts(argc, argv, "createuser", help);
 
-	while ((c = getopt_long(argc, argv, "h:p:U:g:wWedDsSaArRiIlLc:PE",
+	while ((c = getopt_long(argc, argv, "h:p:U:g:wWedDsSrRiIlLc:PE",
 							long_options, &optindex)) != -1)
 	{
 		switch (c)
@@ -121,11 +118,9 @@ main(int argc, char *argv[])
 				createdb = TRI_NO;
 				break;
 			case 's':
-			case 'a':
 				superuser = TRI_YES;
 				break;
 			case 'S':
-			case 'A':
 				superuser = TRI_NO;
 				break;
 			case 'r':