Merge pull request #150 from statisticsnorway/fix/guardian-client-mal…

…formed-json

Send payload to Maskinporten Guardian as json

src/dapla/guardian.py

@@ -77,7 +77,7 @@ def get_guardian_token(
                 "Authorization": "Bearer %s" % keycloak_token,
                 "Content-type": "application/json",
             },
-            data=body,
+            json=body,
         )
         if guardian_response.status_code == 200:
             return t.cast(str, guardian_response.json()["accessToken"])