Previous fix to this failed to account for open_url returning a filehandle (#20097)

* Previous fix to this failed to account for open_url returning a filehandle

Fixes the bugs introduced by c6fb355

* read() from HTTPError for python-3.6+

HTTPError is funny.  It contains a filehandle to read the response from
and also makes it available via a read() method.  On earlier versions of
python (2 and 3) the read() method was enough to make it work with
json.load().  The newer version of json.load() needs a more complete
file interface than this and has stopped working.  Read the bytes,
transform to str and pass it in manually to fix it.

lib/ansible/galaxy/api.py

@@ -93,9 +93,9 @@ class GalaxyAPI(object):
             display.vvv(url)
             resp = open_url(url, data=args, validate_certs=self._validate_certs, headers=headers, method=method,
                             timeout=20)
-            data = json.load(to_text(resp, errors='surrogate_or_strict'))
+            data = json.loads(to_text(resp.read(), errors='surrogate_or_strict'))
         except HTTPError as e:
-            res = json.load(e)
+            res = json.loads(to_text(e.fp.read(), errors='surrogate_or_strict'))
             raise AnsibleError(res['detail'])
         return data
 
@@ -119,7 +119,7 @@ class GalaxyAPI(object):
             raise AnsibleError("Failed to get data from the API server (%s): %s " % (url, to_native(e)))
 
         try:
-            data = json.load(to_text(return_data, errors='surrogate_or_strict'))
+            data = json.loads(to_text(return_data.read(), errors='surrogate_or_strict'))
         except Exception as e:
             raise AnsibleError("Could not process data from the API server (%s): %s " % (url, to_native(e)))
 
@@ -136,7 +136,7 @@ class GalaxyAPI(object):
         url = '%s/tokens/' % self.baseurl
         args = urlencode({"github_token": github_token})
         resp = open_url(url, data=args, validate_certs=self._validate_certs, method="POST")
-        data = json.load(to_text(resp, errors='surrogate_or_strict'))
+        data = json.loads(to_text(resp.read(), errors='surrogate_or_strict'))
         return data
 
     @g_connect