api!: get rid of Qr::FprWithoutAddr variant

We don't look at the address in OPENPGP4FPR QR codes anymore.
If we cannot find a contact by fingerprint,
then we return Qr::FprMismatch without trying to look up
the contact by address.

BREAKING CHANGE: removed DC_QR_FPR_WITHOUT_ADDR constant from CFFI
BREAKING CHANGE: removed FprWithoutAddr variant from JSON-RPC QrObject returned by check_qr

deltachat-jsonrpc/src/api/types/qr.rs

@@ -73,11 +73,6 @@ pub enum QrObject {
         /// Contact ID.
         contact_id: Option<u32>,
     },
-    /// The scanned QR code contains a fingerprint but no e-mail address.
-    FprWithoutAddr {
-        /// Key fingerprint.
-        fingerprint: String,
-    },
     /// Ask the user if they want to create an account on the given domain.
     Account {
         /// Server domain name.
@@ -300,7 +295,6 @@ impl From<Qr> for QrObject {
                 let contact_id = contact_id.map(|contact_id| contact_id.to_u32());
                 QrObject::FprMismatch { contact_id }
             }
-            Qr::FprWithoutAddr { fingerprint } => QrObject::FprWithoutAddr { fingerprint },
             Qr::Account { domain } => QrObject::Account { domain },
             Qr::Backup2 {
                 ref node_addr,