package/python-markdown2: drop patches

package/python-markdown2: drop patches

On master, commit 544007dcc4 itroduced patches to fix CVE-2020-11888.
On next, commit 604fe08806 itroduced the exact same patches for the
exact same reason.

But on next, commit 81b3fd8654 bumped the version and dropped the
patches.

When next was merged into master in commit a6569f2b3d, the patches
introduced by 544007dcc4 (on master) were retained.

Fixes:
 - http://autobuild.buildroot.org/results/bf305c78dddd035b97e88943a1d19a8ceb6b41f7

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
[yann.morin.1998@free.fr: rewrite commit log with detailed explanations]
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>