[deps] Update djangorestframework-gis requirement from ~=1.0 to ~=1.1

Updates the requirements on [djangorestframework-gis](https://github.com/openwisp/django-rest-framework-gis) to permit the latest version.
- [Release notes](https://github.com/openwisp/django-rest-framework-gis/releases)
- [Changelog](https://github.com/openwisp/django-rest-framework-gis/blob/master/CHANGES.rst)
- [Commits](openwisp/django-rest-framework-gis@v1.0.0...v1.1.0)

---
updated-dependencies:
- dependency-name: djangorestframework-gis
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

requirements.txt

@@ -9,7 +9,7 @@ openwisp-users @ https://github.com/openwisp/openwisp-users/tarball/master
 openwisp-utils[celery] @ https://github.com/openwisp/openwisp-utils/tarball/master
 openwisp-notifications @ https://github.com/openwisp/openwisp-notifications/tarball/master
 openwisp-ipam @ https://github.com/openwisp/openwisp-ipam/tarball/master
-djangorestframework-gis~=1.0
+djangorestframework-gis~=1.1
 paramiko[ed25519]~=3.4.0
 scp~=0.15.0
 django-cache-memoize~=0.2.0