Bump Mountpoint to v1.22.1 (#744)

*Issue #, if available:* N/A

*Description of changes:*

Bump Mountpoint for Amazon S3 to
[v1.22.1](https://github.com/awslabs/mountpoint-s3/releases/tag/mountpoint-s3-1.22.1).
- Update `MOUNTPOINT_VERSION` in `Dockerfile` from 1.22.0 to 1.22.1

This 'forwardports' changes from #733.

By submitting this pull request, I confirm that you can use, modify,
copy, and redistribute this contribution, under the terms of your
choice.

Signed-off-by: Jensen Tong <jetong@amazon.com>

Author: jet-tong

Dockerfile

@@ -12,7 +12,7 @@
 #See the License for the specific language governing permissions and
 #limitations under the License.
 
-ARG MOUNTPOINT_VERSION=1.22.0
+ARG MOUNTPOINT_VERSION=1.22.1
 
 # Download the mountpoint tarball and produce an installable directory
 # Building on Amazon Linux 2 because it has an old libc version. libfuse from the os