Return value of IO::Socket::INET.get is Nil on EOF.

According to the implementation of IO::Socket and IO::Socket::INET
the get method returns Nil on end of input, not a type object:

   $line.DEFINITE ?? $line !! Nil

Author: fluca1978

doc/Type/IO/Socket/INET.pod6

@@ -78,8 +78,8 @@ the character(s) that separate lines.
 
     method get()
 
-Reads a line from the socket and returns it. Returns the L<Str|/type/Str> type
-object on end-of-file (EOF).
+Reads a line from the socket and returns it as of type L<Str|/type/Str>.
+Return L<Nil> on end-of-file (EOF).
 
 =head2 method lines