package/tz: fix incorrect timezone setting for uclibc

According to the doc file from <uclibc-src>/docs/
Glibc_vs_uClibc_Differences.txt, the uclibc library read the
TZ environment variable, or the /etc/TZ file; the /etc/TZ file
should be a single line, ending with a newline, containing the
TZ setting.  For example: echo CST6CDT > /etc/TZ

Whereas the tzdump cmd would output two lines like this:
  # Asia/Shanghai
  CST-8

This make the uclibc could not read the correct TZ setting, therefore
e.g. the 'busybox date' cmd always show the UTC timezone.

This fix remove the redundant first line from the tzdump output.

Signed-off-by: Scott Fan <fancp2007@gmail.com>
Tested-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Acked-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>