Make \? output of \dg and \du the same

The previous wording might have suggested that \du only showed login roles
and \dg only group roles, but that is no longer the case.

proposed by Josh Kupershmidt

src/bin/psql/help.c

@@ -207,7 +207,7 @@ slashUsage(unsigned short int pager)
 	fprintf(output, _("  \\dFd[+] [PATTERN]      list text search dictionaries\n"));
 	fprintf(output, _("  \\dFp[+] [PATTERN]      list text search parsers\n"));
 	fprintf(output, _("  \\dFt[+] [PATTERN]      list text search templates\n"));
-	fprintf(output, _("  \\dg[+]  [PATTERN]      list roles (groups)\n"));
+	fprintf(output, _("  \\dg[+]  [PATTERN]      list roles\n"));
 	fprintf(output, _("  \\di[S+] [PATTERN]      list indexes\n"));
 	fprintf(output, _("  \\dl                    list large objects, same as \\lo_list\n"));
 	fprintf(output, _("  \\dn[+]  [PATTERN]      list schemas\n"));
@@ -217,7 +217,7 @@ slashUsage(unsigned short int pager)
 	fprintf(output, _("  \\ds[S+] [PATTERN]      list sequences\n"));
 	fprintf(output, _("  \\dt[S+] [PATTERN]      list tables\n"));
 	fprintf(output, _("  \\dT[S+] [PATTERN]      list data types\n"));
-	fprintf(output, _("  \\du[+]  [PATTERN]      list roles (users)\n"));
+	fprintf(output, _("  \\du[+]  [PATTERN]      list roles\n"));
 	fprintf(output, _("  \\dv[S+] [PATTERN]      list views\n"));
 	fprintf(output, _("  \\l[+]                  list all databases\n"));
 	fprintf(output, _("  \\sf[+] FUNCNAME        show a function's definition\n"));