package/gnupg2: bump version to 2.1.19

package/gnupg2: bump version to 2.1.19

Support for GnuPG 2.0 will end 2017-12-31:
https://lists.gnupg.org/pipermail/gnupg-announce/2017q1/000402.html

Removed all patches:

- 0001-fix-pth-config-usage.patch
  Not needed anymore, gnupg2 now depends on libnpth:
  https://git.gnupg.org/cgi-bin/gitweb.cgi?p=gnupg.git;a=commitdiff;h=001352077cdc7e402421c77328bea1a052005673

- 0002-missing-include.patch
  Not needed anymore after upstream commit
  https://git.gnupg.org/cgi-bin/gitweb.cgi?p=gnupg.git;a=commitdiff;h=0367a4b8cfbf1f197e093ca2b83b27e0a409c3c7

- 0003-dont-run-tests.patch
  Not needed anymore after upstream commit
  https://git.gnupg.org/cgi-bin/gitweb.cgi?p=gnupg.git;a=commitdiff;h=4a232d23a8f51bebf9ee382e480248b4bde30f28

- 0004-silence-git-when-not-in-git-tree.patch
  Not needed anymore after upstream commit restricting the usage of git
  commands to the case where the directory .git exists
  https://git.gnupg.org/cgi-bin/gitweb.cgi?p=gnupg.git;a=commitdiff;h=b67e4e523e6d19d384e23c5bb03010caebd150e7

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>