test: suppress deprecation warning from selenium internals (ietf-tools#4836)

Author: jennifer-richards

ietf/settings.py

@@ -18,7 +18,7 @@
 warnings.filterwarnings("ignore", message="Report.file_reporters will no longer be available in Coverage.py 4.2", module="coverage.report")
 warnings.filterwarnings("ignore", message="{% load staticfiles %} is deprecated")
 warnings.filterwarnings("ignore", message="Using or importing the ABCs from 'collections' instead of from 'collections.abc' is deprecated", module="bleach")
-
+warnings.filterwarnings("ignore", message="HTTPResponse.getheader\(\) is deprecated", module='selenium.webdriver')
 try:
     import syslog
     syslog.openlog(str("datatracker"), syslog.LOG_PID, syslog.LOG_USER)