Fix groestlcoin address parsing

Baesd on erasmospunk's PR #551

electrumx/lib/coins.py

@@ -2062,11 +2062,17 @@ class Groestlcoin(Coin):
         'xkj42efxrcy6vbfw.onion t',
     ]
 
+    def grshash(data):
+        import groestlcoin_hash
+        return groestlcoin_hash.getHash(data, len(data))
+
     @classmethod
     def header_hash(cls, header):
         '''Given a header return the hash.'''
-        import groestlcoin_hash
-        return groestlcoin_hash.getHash(header, len(header))
+        return cls.grshash(header)
+
+    ENCODE_CHECK = partial(Base58.encode_check, hash_fn=grshash)
+    DECODE_CHECK = partial(Base58.decode_check, hash_fn=grshash)
 
 
 class GroestlcoinTestnet(Groestlcoin):

tests/lib/test_addresses.py

@@ -51,6 +51,8 @@ addresses = [
      "2789d58cfa0957d206f025c2af056fc8a77cebb0", "8cc9b11122272bd7b79a50"),
     (coins.Decred, "DcuQKx8BES9wU7C6Q5VmLBjw436r27hayjS",
      "f0b4e85100aee1a996f22915eb3c3f764d53779a", "a03c1a27de9ac3b3122e8d"),
+    (coins.Groestlcoin, "FY7vmDL7FZGACwqVNx5p4fVaGghojWM5AF",
+     "206168f5322583ff37f8e55665a4789ae8963532", "b8cb80b26e8932f5b12a7e"),
 ]