[HostIp] Update composer.json

Remove extension dependencies ; seems to break Scrutinizer CI analysis
See https://scrutinizer-ci.com/g/geocoder-php/host-ip-provider/inspections/69b92d79-313e-4901-9e6c-1b1210f2e153

Author: jbelien

composer.json

@@ -13,8 +13,6 @@
     ],
     "require": {
         "php": "^7.2",
-        "ext-simplexml": "*",
-        "ext-json": "*",
         "geocoder-php/common-http": "^4.0",
         "willdurand/geocoder": "^4.0"
     },