Use built-in method in _get_backend (#406)

Co-authored-by: Amin Alaee <[email protected]>

Author: manlix

databases/core.py

@@ -221,10 +221,9 @@ def force_rollback(self) -> typing.Iterator[None]:
             self._force_rollback = initial
 
     def _get_backend(self) -> str:
-        try:
-            return self.SUPPORTED_BACKENDS[self.url.scheme]
-        except KeyError:
-            return self.SUPPORTED_BACKENDS[self.url.dialect]
+        return self.SUPPORTED_BACKENDS.get(
+            self.url.scheme, self.SUPPORTED_BACKENDS[self.url.dialect]
+        )
 
 
 class Connection: