adb: Fix 'adb forward --no-rebind'.

Due to a typo, the --no-rebind option never worked (it always failed).
The root of the problem was that the client was sending on the wire
a command like:

  host:forward:norebind::tcp:<port>;tcp:<port>
                       ^^
Instead of:

  host:forward:norebind:tcp:<port>;tcp:<port>
                       ^

Note the erroneous double-column.

The fix is local to the adb client and thus doesn't require a new
version of the server or guest adbd on the device-side.

This also fixes 'adb reverse --no-rebind'.

See https://code.google.com/p/chromium/issues/detail?id=451109

Change-Id: I680fd432b5470072f6a9968ca32a7f90c600ac68