version code bump + modified changelog

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ### Version 2.5.12
 * Jingle file transfer fixes
+* Fixed OMEMO self healing (after backup restore) on servers w/o MAM
 
 ### Version 2.5.11
 * Fixed crash on Android <5.0

build.gradle

@@ -84,7 +84,7 @@ android {
     defaultConfig {
         minSdkVersion 16
         targetSdkVersion 28
-        versionCode 343
+        versionCode 346
         versionName "2.5.12"
         archivesBaseName += "-$versionName"
         applicationId "eu.siacs.conversations"