contrib/upnp: disable IPv6 support on iOS/tvOS

Browsing IPv6 servers is unsupported by libupnp on iOS and tvOS leading
to an empty content directory. This is mitigated by disabling IPv6
support just like for WinRT.

Fixes #26301

contrib/src/upnp/rules.mak

@@ -22,8 +22,12 @@ endif
 ifdef HAVE_WINSTORE
 CONFIGURE_ARGS=--disable-ipv6 --enable-unspecified_server
 else
+ifdef HAVE_IOS
+CONFIGURE_ARGS=--disable-ipv6 --enable-unspecified_server
+else
 CONFIGURE_ARGS=--enable-ipv6
 endif
+endif
 ifndef WITH_OPTIMIZATION
 CONFIGURE_ARGS += --enable-debug
 endif