PG19 warning errors

[robe2]

I get these error warnings when compiling against PG19 beta1

http.c:421:1: error: function declaration isn’t a prototype [-Werror=strict-prototypes]
  421 | http_guc_init()
      | ^~~~~~~~~~~~~
http.c: In function ‘http_guc_init’:
http.c:421:1: error: old-style function definition [-Werror=old-style-definition]
http.c: At top level:
http.c:975:1: error: function declaration isn’t a prototype [-Werror=strict-prototypes]
  975 | http_get_handle()
      | ^~~~~~~~~~~~~~~
http.c: In function ‘http_get_handle’:
http.c:975:1: error: old-style function definition [-Werror=old-style-definition]
cc1: all warnings being treated as errors
make: *** [<builtin>: http.o] Error 1

I'll send a pull request soon.