Fix session retrieve in examine, update changelog

CHANGELOG.md

@@ -31,6 +31,7 @@ without arguments starts a full interactive Python console.
 - Show warning on `start -l` if settings contains values unsafe for production.
 - Make code auto-formatted with Black.
 - Make default `set` command able to edit nested structures (PR by Aaron McMillan)
+- Allow running Evennia test suite from core repo with `make test`.
 
 
 ## Evennia 0.9 (2018-2019)

evennia/commands/default/building.py

@@ -2579,9 +2579,10 @@ class CmdExamine(ObjManipCommand):
                     # we are only interested in specific attributes
                     caller.msg(self.format_attributes(obj, attrname, crop=False))
             else:
-                session = obj.sessions.get()[0]
+                session = None
                 if obj.sessions.count():
                     mergemode = "session"
+                    session = obj.sessions.get()[0]
                 elif self.account_mode:
                     mergemode = "account"
                 else: