make INFINITY from Jacobi easier to print

Author: tomato42

src/ecdsa/ellipticcurve.py

@@ -1289,6 +1289,9 @@ def curve(self):
     def order(self):
         return self.__order
 
+    def to_affine(self):
+        return self
+
 
 class PointEdwards(AbstractPoint):
     """Point on Twisted Edwards curve.