Fix crash with formatting emails in recipient settings.

Fixes #7868

src/org/thoughtcrime/securesms/RecipientPreferenceActivity.java

@@ -359,7 +359,7 @@ public class RecipientPreferenceActivity extends PassphraseRequiredActionBarActi
         colorPreference.setColors(MaterialColors.CONVERSATION_PALETTE.asConversationColorArray(getActivity()));
         colorPreference.setColor(recipient.getColor().toActionBarColor(getActivity()));
 
-        aboutPreference.setTitle(PhoneNumberUtils.formatNumber(recipient.getAddress().toPhoneString()));
+        aboutPreference.setTitle(formatAddress(recipient.getAddress()));
         aboutPreference.setSummary(recipient.getCustomLabel());
         aboutPreference.setSecure(recipient.getRegistered() == RecipientDatabase.RegisteredState.REGISTERED);
 
@@ -388,6 +388,12 @@ public class RecipientPreferenceActivity extends PassphraseRequiredActionBarActi
       }
     }
 
+    private @NonNull String formatAddress(@NonNull Address address) {
+      if      (address.isPhone()) return PhoneNumberUtils.formatNumber(address.toPhoneString());
+      else if (address.isEmail()) return address.toEmailString();
+      else                        return "";
+    }
+
     private @NonNull String getRingtoneSummary(@NonNull Context context, @Nullable Uri ringtone) {
       if (ringtone == null) {
         return context.getString(R.string.preferences__default);