csp_report_uri caused a cyclic dependency

IPython/html/base/handlers.py

@@ -32,7 +32,7 b' from IPython.utils.path import filefind'
 from IPython.utils.py3compat import string_types
 from IPython.html.utils import is_hidden, url_path_join, url_escape
 
-from IPython.html.services.security.handlers import csp_report_uri
+from IPython.html.services.security import csp_report_uri
 
 #-----------------------------------------------------------------------------
 # Top-level handlers

IPython/html/services/security/__init__.py

@@ -0,0 +1,1 b''
+csp_report_uri = r"/api/security/csp-report"