fixed get_script_run_ctx

app/SessionState.py

@@ -15,13 +15,8 @@ result:
 >>> session_state.user_name
 'Mary'
 """
-try:
-    import streamlit.ReportThread as ReportThread
-    from streamlit.server.Server import Server
-except Exception:
-    # Streamlit >= 0.65.0
-    import streamlit.report_thread as ReportThread
-    from streamlit.server.server import Server
+from streamlit.script_run_context import get_script_run_ctx
+from streamlit.server.Server import Server
 
 
 class SessionState(object):
@@ -67,7 +62,7 @@ def get(**kwargs):
     """
     # Hack to get the session object from Streamlit.
 
-    ctx = ReportThread.get_report_ctx()
+    ctx = get_script_run_ctx()
 
     this_session = None