enable malloc stack logging

deltachat-ios.xcodeproj/xcshareddata/xcschemes/deltachat-ios.xcscheme

@@ -57,7 +57,6 @@
       useCustomWorkingDirectory = "NO"
       ignoresPersistentStateOnLaunch = "NO"
       debugDocumentVersioning = "YES"
-      stopOnEveryMainThreadCheckerIssue = "YES"
       migratedStopOnEveryIssue = "YES"
       debugServiceExtension = "internal"
       allowLocationSimulation = "YES">
@@ -71,6 +70,18 @@
             ReferencedContainer = "container:deltachat-ios.xcodeproj">
          </BuildableReference>
       </BuildableProductRunnable>
+      <AdditionalOptions>
+         <AdditionalOption
+            key = "MallocStackLogging"
+            value = ""
+            isEnabled = "YES">
+         </AdditionalOption>
+         <AdditionalOption
+            key = "PrefersMallocStackLoggingLite"
+            value = ""
+            isEnabled = "YES">
+         </AdditionalOption>
+      </AdditionalOptions>
    </LaunchAction>
    <ProfileAction
       buildConfiguration = "Release"