import: Make sure the internal realm is created before import.

This is critical for importing the very first realm into an empty
server, since in 27b15a9722, we changed
the model to create the internal realm when the first real realm would
be created, but neglected the data import code path.

zerver/lib/import_realm.py

@@ -29,6 +29,7 @@ from zerver.lib.upload import random_name, sanitize_name, \
     guess_type, BadImageError
 from zerver.lib.utils import generate_api_key, process_list_in_batches
 from zerver.lib.parallel import run_parallel
+from zerver.lib.server_initialization import server_initialized, create_internal_realm
 from zerver.models import UserProfile, Realm, Client, Huddle, Stream, \
     UserMessage, Subscription, Message, RealmEmoji, \
     RealmDomain, Recipient, get_user_profile_by_id, \
@@ -758,6 +759,9 @@ def do_import_realm(import_dir: Path, subdomain: str, processes: int=1) -> Realm
     if not os.path.exists(realm_data_filename):
         raise Exception("Missing realm.json file!")
 
+    if not server_initialized():
+        create_internal_realm()
+
     logging.info("Importing realm data from %s" % (realm_data_filename,))
     with open(realm_data_filename) as f:
         data = ujson.load(f)