package/proftpd: security bump to version 1.3.6c

Fixes the following security issues:

- CVE-2020-9273: In ProFTPD 1.3.7, it is possible to corrupt the memory pool
  by interrupting the data transfer channel.  This triggers a use-after-free
  in alloc_pool in pool.c, and possible remote code execution.

And additionally, fixes a number of other issues.  For details, see the
release notes:

https://github.com/proftpd/proftpd/blob/1.3.6/RELEASE_NOTES

This also bumps the bundled libcap, so
0001-fix-kernel-header-capability-version.patch can be dropped.

While we are at it, adjust the white space in the .hash function to match
the new agreements.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit a1859b6204e0deadec4377fe4e6813a97c8d3fa0)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/proftpd/0001-fix-kernel-header-capability-version.patch

@@ -1,12 +0,0 @@
---- a/lib/libcap/libcap.h	2008-08-22 19:49:48.000000000 -0700
-+++ b/lib/libcap/libcap.h	2010-10-06 15:31:11.000000000 -0700
-@@ -65,7 +65,8 @@ struct _cap_struct {
-  */
- 
- #if !defined(_LINUX_CAPABILITY_VERSION_1) || \
--            (_LINUX_CAPABILITY_VERSION_1 != 0x19980330)
-+            ((_LINUX_CAPABILITY_VERSION_1 != 0x19980330) && \
-+            (_LINUX_CAPABILITY_VERSION_1 != 0x20071026))
- 
- # error "Kernel <linux/capability.h> does not match library"
- # error "file "libcap.h" --> fix and recompile libcap"

package/proftpd/proftpd.hash

@@ -1,3 +1,3 @@
 # Locally calculated
-sha256 fe5baf6c469a2b0b7f0e2611561b6fd5414300e32a76b96adb2ccfe05b5efb60 proftpd-1.3.6b.tar.gz
-sha256 391a473d755c29b5326fb726326ff3c37e42512f53a8f5789fc310232150bf80 COPYING
+sha256  fa3541c4b34136a7b80cb12a2f6f9a0cab5118a5b0a1653d40af49c6479c35ad  proftpd-1.3.6c.tar.gz
+sha256  391a473d755c29b5326fb726326ff3c37e42512f53a8f5789fc310232150bf80  COPYING

package/proftpd/proftpd.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-PROFTPD_VERSION = 1.3.6b
+PROFTPD_VERSION = 1.3.6c
 PROFTPD_SITE = $(call github,proftpd,proftpd,v$(PROFTPD_VERSION))
 PROFTPD_LICENSE = GPL-2.0+
 PROFTPD_LICENSE_FILES = COPYING