Fixed collapsing messages

app/src/main/java/eu/faircode/email/FragmentMessages.java

@@ -2478,14 +2478,14 @@ public class FragmentMessages extends FragmentBase {
                 return true;
             }
 
-            if (values.containsKey("expanded")) {
+            int count = (values.containsKey("expanded") ? values.get("expanded").size() : 0);
             SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(getContext());
-                if (values.get("expanded").size() > 1 || prefs.getBoolean("collapse", false)) {
+            boolean collapse = prefs.getBoolean("collapse", false);
+            if ((count == 1 && collapse) || count > 1) {
                 values.get("expanded").clear();
                 adapter.notifyDataSetChanged();
                 return true;
             }
-            }
 
             return false;
         }