Interaction: cleanup

Change-Id: I5f5fad507c0812eecc721b494ef602c8c7dc35dc

jami-android/libjamiclient/src/main/kotlin/net/jami/model/Interaction.kt

@@ -277,7 +277,7 @@ open class Interaction {
 
         fun compare(a: Interaction?, b: Interaction?): Int {
             if (a == null) return if (b == null) 0 else -1
-            return if (b == null) 1 else java.lang.Long.compare(a.timestamp, b.timestamp)
+            return if (b == null) 1 else a.timestamp.compareTo(b.timestamp)
         }
     }
 }
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