refactor: ignore public key argument in dc_preconfigure_keypair()

Public key can be extracted from the secret key file.

python/src/deltachat/account.py

@@ -195,7 +195,7 @@ class Account:
         assert res != ffi.NULL, f"config value not found for: {name!r}"
         return from_dc_charpointer(res)
 
-    def _preconfigure_keypair(self, addr: str, public: str, secret: str) -> None:
+    def _preconfigure_keypair(self, addr: str, secret: str) -> None:
         """See dc_preconfigure_keypair() in deltachat.h.
 
         In other words, you don't need this.
@@ -203,7 +203,7 @@ class Account:
         res = lib.dc_preconfigure_keypair(
             self._dc_context,
             as_dc_charpointer(addr),
-            as_dc_charpointer(public),
+            ffi.NULL,
             as_dc_charpointer(secret),
         )
         if res == 0:

python/src/deltachat/testplugin.py

@@ -478,10 +478,9 @@ class ACFactory:
         except IndexError:
             pass
         else:
-            fname_pub = self.data.read_path(f"key/{keyname}-public.asc")
             fname_sec = self.data.read_path(f"key/{keyname}-secret.asc")
-            if fname_pub and fname_sec:
-                account._preconfigure_keypair(addr, fname_pub, fname_sec)
+            if fname_sec:
+                account._preconfigure_keypair(addr, fname_sec)
                 return True
             print(f"WARN: could not use preconfigured keys for {addr!r}")