fix: Prevent crash by keeping network.model.** classes (#369)

Previous rule didn't consider a deeper package hierarchy, so the new
NodeInfo classes were being removed by ProGuard.

app/proguard-rules.pro

@@ -38,7 +38,7 @@
 # Pachli specific options
 
 # keep members of our model classes, they are used in json de/serialization
--keepclassmembers class app.pachli.core.network.model.* { *; }
+-keepclassmembers class app.pachli.core.network.model.** { *; }
 
 -keep public enum app.pachli.core.network.model.*$** {
     **[] $VALUES;