Bump lxml from 4.6.2 to 4.6.3 in /deploy

Bumps [lxml](https://github.com/lxml/lxml) from 4.6.2 to 4.6.3.
- [Release notes](https://github.com/lxml/lxml/releases)
- [Changelog](https://github.com/lxml/lxml/blob/master/CHANGES.txt)
- [Commits](https://github.com/lxml/lxml/compare/lxml-4.6.2...lxml-4.6.3)

Signed-off-by: dependabot[bot] <support@github.com>

deploy/requirements.txt

@@ -37,7 +37,7 @@ jdcal==1.4.1
 jinja2==2.11.3
 jsonschema==3.2.0
 ldap3==2.8.1
-lxml==4.6.2
+lxml==4.6.3
 mako==1.1.3
 markdown==3.3.3
 markupsafe==1.1.1