Fix out-of-bound access in KeySymToUcs4()

Array `keysym_to_unicode_590_5fe` is only valid for range  [0x590, 0x5fe] but current lower-bound is checked against 0x589.

So invalid values from 0x58a to 0x58f are being allowed by current check.

If any of these invalid value is passed as `keysym`,    `keysym - 0x590` would underflow.

Signed-off-by: Gaurav Ujjwal <gujjwal00@gmail.com>
4 jobs for gujjwal00-master-patch-66979 in 10 minutes and 3 seconds (queued for 4 seconds)
Status Job ID Name Coverage
  Prep
passed #9608016
check-commits

00:00:39

passed #9608017
container-prep

00:00:12

 
  Build
passed #9608018
build

00:08:45

 
  Deploy
failed #9608019
allowed to fail
check-merge-request

00:00:39

 
Name Stage Failure
failed
check-merge-request Deploy
  File "/usr/local/lib/python3.9/site-packages/gitlab/exceptions.py", line 289, in wrapped_f
raise error(e.error_message, e.response_code, e.response_body) from e
gitlab.exceptions.GitlabGetError: 404: 404 Project Not Found
Uploading artifacts for failed job
Uploading artifacts...
WARNING: results.xml: no matching files
ERROR: No files to upload
Cleaning up file based variables
ERROR: Job failed: exit code 1