Reset GUCs at the end of regression tests. (#300)

Fixes spurious test failures if the test order is not as expected.

Author: adamguo0

test/expected/pg_tle_api.out

@@ -464,6 +464,15 @@ SELECT pgtle.unregister_feature('password_check_length_greater_than_8', 'clienta
 (1 row)
 
 -- now drop everything
+ALTER SYSTEM RESET pgtle.enable_password_check;
+ALTER SYSTEM RESET pgtle.passcheck_db_name;
+SELECT pg_reload_conf();
+ pg_reload_conf 
+----------------
+ t
+(1 row)
+
+\c
 DROP FUNCTION password_check_length_greater_than_8;
 DROP SCHEMA pass CASCADE;
 NOTICE:  drop cascades to function pass.password_check_length_greater_than_8(text,text,pgtle.password_types,timestamp with time zone,boolean)

test/sql/pg_tle_api.sql

@@ -267,6 +267,10 @@ SELECT pg_reload_conf();
 SELECT pgtle.register_feature('password_check_length_greater_than_8', 'clientauth');
 SELECT pgtle.unregister_feature('password_check_length_greater_than_8', 'clientauth');
 -- now drop everything
+ALTER SYSTEM RESET pgtle.enable_password_check;
+ALTER SYSTEM RESET pgtle.passcheck_db_name;
+SELECT pg_reload_conf();
+\c
 DROP FUNCTION password_check_length_greater_than_8;
 DROP SCHEMA pass CASCADE;
 DROP EXTENSION pg_tle;