Fix mypy boolean condition use

src/login.py

@@ -62,6 +62,6 @@ def check_password():
 
     # Show inputs for email + password.
     login_form()
-    if st.session_state.get("password_correct", True) == False:
+    if st.session_state.get("password_correct", True) is False:
         st.error("😕 User not known or password incorrect")
     return False