Move the v, r, s for catching exception

mythril/laser/ethereum/natives.py

@@ -32,14 +32,16 @@ def extract32(data, i):
 
 
 def ecrecover(data):
+
     try:
         data = bytearray(data)
-    except TypeError:
-        raise NativeContractException
-    message = b''.join([ALL_BYTES[x] for x in data[0:32]])
         v = extract32(data, 32)
         r = extract32(data, 64)
         s = extract32(data, 96)
+    except TypeError:
+        raise NativeContractException
+
+    message = b''.join([ALL_BYTES[x] for x in data[0:32]])
     if r >= secp256k1n or s >= secp256k1n or v < 27 or v > 28:
         return []
     try: