fix: Fixes jsonld issue when importing from dataverse (#759)

* fix: Fixes jsonld issue when importing from dataverse

Author: Panaetius

renku/core/models/jsonld.py

@@ -418,6 +418,8 @@ def from_jsonld(
         if data['@context'] != cls._jsonld_context:
             # merge new context into old context to prevent properties
             # getting lost in jsonld expansion
+            if isinstance(data['@context'], str):
+                data['@context'] = {'@base': data['@context']}
             data['@context'].update(cls._jsonld_context)
             try:
                 compacted = ld.compact(data, cls._jsonld_context)