Add 1.5.5 to the bug report template

Author: StephenCWills

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -28,6 +28,7 @@ body:
     attributes:
       label: DevilutionX version
       options:
+        - 1.5.5
         - 1.5.4
         - 1.5.3
         - 1.5.2