response.buffer() and blob fields doesn't exist in ReactNative

Add a check for ReactNative next to the checks for node/browsers so that we don't throw errors using unsupported API's.

Fixes pouchdb#7688.

packages/node_modules/pouchdb-adapter-http/src/index.js

@@ -506,7 +506,7 @@ function HttpPouch(opts, callback) {
         var path = encodeDocId(doc._id) + '/' + encodeAttachmentId(filename) +
             '?rev=' + doc._rev;
         return ourFetch(genDBUrl(host, path)).then(function (response) {
-          if (typeof process !== 'undefined' && !process.browser) {
+          if (typeof process !== 'undefined' && !process.browser && !(typeof navigator != 'undefined' && navigator.product == 'ReactNative')) {
             return response.buffer();
           } else {
             /* istanbul ignore next */
@@ -515,7 +515,7 @@ function HttpPouch(opts, callback) {
         }).then(function (blob) {
           if (opts.binary) {
             // TODO: Can we remove this?
-            if (typeof process !== 'undefined' && !process.browser) {
+            if (typeof process !== 'undefined' && !process.browser && !(typeof navigator != 'undefined' && navigator.product == 'ReactNative')) {
               blob.type = att.content_type;
             }
             return blob;