Update ISSUE_TEMPLATE.md (#8695)

* Update ISSUE_TEMPLATE.md

* Update ISSUE_TEMPLATE.md

.github/ISSUE_TEMPLATE.md

@@ -5,7 +5,7 @@
 ##### Three.js version
 
 - [ ] Dev
-- [ ] r75
+- [ ] r76
 - [ ] ...
 
 ##### Browser