Fix IPv6 random addresses (Pekka Pietikäinen), closes #5086 and #5136)

scapy/volatile.py

@@ -294,7 +294,7 @@ class RandIP6(RandString):
                     remain = random.randint(0,remain)
                 for j in range(remain):
                     ip.append("%04x" % random.randint(0,65535))
-            if n == 0:
+            elif n == 0:
               ip.append("0")
             elif not n:
                 ip.append("")