tests/conftest.py: fix test for modifying another users' shares

sachet/server/files/views.py

@@ -122,7 +122,7 @@ class FileContentAPI(ModelAPI):
                 jsonify(
                     {
                         "status": "fail",
-                        "message": "Share must be initialized by its owner.",
+                        "message": "Share must be modified by its owner.",
                     }
                 ),
                 403,

tests/conftest.py

@@ -75,7 +75,10 @@ def users(client):
         dave=dict(
             password="1234",
             permissions=Bitmask(
-                Permissions.CREATE, Permissions.READ, Permissions.DELETE
+                Permissions.CREATE,
+                Permissions.READ,
+                Permissions.DELETE,
+                Permissions.MODIFY,
             ),
         ),
         # admins don't have the other permissions by default,