import private headers to make incomplete structs visible for Swift

deltachat-ios/deltachat-ios-Bridging-Header.h

@@ -3,4 +3,10 @@
 //
 
 #include "mrmailbox.h"
+#include "mrmailbox-private.h"
+#include "mrcontact-private.h"
+#include "mrchatlist-private.h"
+#include "mrmsg-private.h"
+#include "mrchat-private.h"
+#include "mrlot-private.h"
 #include "wrapper.h"