Fix psql's \? output for \watch

It was reported as misaligned by Kyotaro, but it also needed to be
turned into a single translatable phrase (like the one for \g is), as
reported by Yugo.

This is a new issue (commit f347ec7), so no backpatch is needed.

Author: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Author: Yugo NAGATA <nagata@sraoss.co.jp>
Discussion: https://postgr.es/m/20230907.142956.2038600444404289870.horikyota.ntt@gmail.com

Author: alvherre

src/bin/psql/help.c

@@ -200,9 +200,9 @@ slashUsage(unsigned short int pager)
 	HELP0("  \\gset [PREFIX]         execute query and store result in psql variables\n");
 	HELP0("  \\gx [(OPTIONS)] [FILE] as \\g, but forces expanded output mode\n");
 	HELP0("  \\q                     quit psql\n");
-	HELP0("  \\watch [[i=]SEC] [c=N] [m=MIN]\n");
-	HELP0("                          execute query every SEC seconds, up to N times\n");
-	HELP0("                          stop if less than MIN rows are returned\n");
+	HELP0("  \\watch [[i=]SEC] [c=N] [m=MIN]\n"
+		  "                         execute query every SEC seconds, up to N times\n"
+		  "                         stop if less than MIN rows are returned\n");
 	HELP0("\n");
 
 	HELP0("Help\n");