Use uri_string module instead of the deprecated http_uri

http_uri is marked for deprecation since OTP 23
Use uri_string which is available since OTP 21
No need to provide alternative, because it's used only by mod_matrix,
and this runs only with Erlang/OTP 24 or higher.

https://www.erlang.org/patches/otp-23.0#inets-7.2
https://www.erlang.org/docs/23/man/http_uri

src/mod_matrix_gw.erl

@@ -743,7 +743,7 @@ sign_json(Host, JSON) ->
 send_request(Host, Method, MatrixServer, Path, Query, JSON,
              HTTPOptions, Options) ->
     URI1 = iolist_to_binary(
-             lists:map(fun(P) -> [$/, http_uri:encode(P)] end, Path)),
+             lists:map(fun(P) -> [$/, uri_string:quote(P)] end, Path)),
     URI =
         case Query of
             [] -> URI1;
@@ -751,7 +751,7 @@ send_request(Host, Method, MatrixServer, Path, Query, JSON,
                 URI2 = str:join(
                          lists:map(
                            fun({K, V}) ->
-                                   [http_uri:encode(K), $=, http_uri:encode(V)]
+                                   [uri_string:quote(K), $=, uri_string:quote(V)]
                            end, Query), $&),
                 <<URI1/binary, $?, URI2/binary>>
         end,