Fix documentation bug 25857: the universe is ::/0, not ::/128

Patch from CTassisF.

changes/25857

@@ -0,0 +1,3 @@
+  o Documentation:
+    - Correct an IPv6 error in the documentation for ExitPolicy.
+      Closes ticket 25857.  Patch from "CTassisF".

doc/tor.1.txt

@@ -1835,8 +1835,8 @@ is non-zero):
     "**accept[6]**|**reject[6]**  __ADDR__[/__MASK__][:__PORT__]". If /__MASK__ is
     omitted then this policy just applies to the host given. Instead of giving
     a host or network you can also use "\*" to denote the universe (0.0.0.0/0
-    and ::/128), or \*4 to denote all IPv4 addresses, and \*6 to denote all
-    IPv6 addresses.
+    and ::/0), or \*4 to denote all IPv4 addresses, and \*6 to denote all IPv6
+    addresses.
     __PORT__ can be a single port number, an interval of ports
     "__FROM_PORT__-__TO_PORT__", or "\*". If __PORT__ is omitted, that means
     "\*". +