Fixed case comparison for contacts list headers

CHANGELOG.md

@@ -14,6 +14,7 @@ Group changes to describe their impact on the project, as follows:
 
 ### Fixed
 - Negative gain in audio settings is allowed again
+- Contacts list header case comparison
 
 ## [4.6.1] - 2022-02-14
 

app/src/main/java/org/linphone/activities/main/contact/adapters/ContactsListAdapter.kt

@@ -105,7 +105,7 @@ class ContactsListAdapter(
         val previousPosition = position - 1
         return if (previousPosition >= 0) {
             val previousItemFirstLetter = getItem(previousPosition).name.first().toString()
-            previousItemFirstLetter != firstLetter
+            !firstLetter.equals(previousItemFirstLetter, ignoreCase = true)
         } else true
     }