Merge #1588: Reword warning for non-unique provider key kind

d4dd7b3dbf4ab287f7e289b5b49d244fb6b44868 Reword warning for non-unique provider key kind (Michael Mallan)

Pull request description:

  This simplifies the warning message for the user in case a fetched provider key (more precisely, any key with the same fingerprint) has already been added to the wallet (as a different key kind).

ACKs for top commit:
  edouardparis:
    ACK d4dd7b3dbf4ab287f7e289b5b49d244fb6b44868

Tree-SHA512: b009955694a96e1a8929fbbd5a6254bc1ec227e0ad3de29018738c5aaa868f64892f84a726cc87fa1a72ef15bc290fed2fa971a0516b058a02c143b9c26a6803

liana-gui/src/installer/step/descriptor/editor/key.rs

@@ -266,7 +266,10 @@ impl super::DescriptorEditModal for EditXpubModal {
                                         && existing.source.provider_key_kind()
                                             != key.source.provider_key_kind()
                                 }) {
-                                    Some("Two keys with the same fingerprint must have the same provider key kind.".to_string())
+                                    Some(
+                                        "Fetched key has already been added to the wallet."
+                                            .to_string(),
+                                    )
                                 } else {
                                     None
                                 };