[deps] Update openwisp-utils[rest] requirement from ~=1.1.0 to ~=1.1.1

Updates the requirements on [openwisp-utils[rest]](https://github.com/openwisp/openwisp-utils) to permit the latest version.
- [Release notes](https://github.com/openwisp/openwisp-utils/releases)
- [Changelog](https://github.com/openwisp/openwisp-utils/blob/master/CHANGES.rst)
- [Commits](openwisp/openwisp-utils@1.1.0...1.1.1)

---
updated-dependencies:
- dependency-name: openwisp-utils[rest]
  dependency-type: direct:production
...

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

requirements.txt

@@ -1,4 +1,4 @@
 openwisp-users @ https://github.com/openwisp/openwisp-users/tarball/master
-openwisp-utils[rest]~=1.1.0
+openwisp-utils[rest]~=1.1.1
 django-reversion~=5.1.0
 openpyxl~=3.1.5