Protects against exceptions when creating keys with invalid bytearrays.

app/src/main/java/com/vitorpamplona/amethyst/model/Account.kt

@@ -877,6 +877,7 @@ class Account(
                     null
                 }
 
+                try {
                     if (altPrivateKeyToUse != null && altPubkeyToUse != null) {
                         val altPubKeyFromPrivate = Utils.pubkeyCreate(altPrivateKeyToUse).toHexKey()
 
@@ -896,6 +897,10 @@ class Account(
                     } else {
                         null
                     }
+                } catch (e: Exception) {
+                    Log.e("Account", "Failed to create pubkey for ZapRequest ${event.id}", e)
+                    null
+                }
             }
         } else {
             null