psql: Add tab completion for subscription wal_receiver_timeout

Commit fb80f38 added wal_receiver_timeout as a CREATE/ALTER
SUBSCRIPTION option, but psql tab completion did not include it in the
subscription option lists.

Add wal_receiver_timeout to completion for CREATE SUBSCRIPTION ... WITH
and ALTER SUBSCRIPTION ... SET.

Author: Chao Li <lic@highgo.com>
Reviewed-by: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Reviewed-by: Xuneng Zhou <xunengzhou@gmail.com>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/BBC5628A-63C0-4436-B8F3-90AF59BBEB73@gmail.com

Author: MasaoFujii

src/bin/psql/tab-complete.in.c

@@ -2380,7 +2380,8 @@ match_previous_words(int pattern_id,
 					  "max_retention_duration", "origin",
 					  "password_required", "retain_dead_tuples",
 					  "run_as_owner", "slot_name", "streaming",
-					  "synchronous_commit", "two_phase");
+					  "synchronous_commit", "two_phase",
+					  "wal_receiver_timeout");
 	/* ALTER SUBSCRIPTION <name> SKIP ( */
 	else if (Matches("ALTER", "SUBSCRIPTION", MatchAny, MatchAnyN, "SKIP", "("))
 		COMPLETE_WITH("lsn");
@@ -3965,7 +3966,8 @@ match_previous_words(int pattern_id,
 					  "max_retention_duration", "origin",
 					  "password_required", "retain_dead_tuples",
 					  "run_as_owner", "slot_name", "streaming",
-					  "synchronous_commit", "two_phase");
+					  "synchronous_commit", "two_phase",
+					  "wal_receiver_timeout");
 
 /* CREATE TRIGGER --- is allowed inside CREATE SCHEMA, so use TailMatches */