package/pkgconf: purge trailing '/' from PKGCONF_SITE

<PKG>_SITE cannot have a trailing slash.

This was not detected by the check in generic-package because it is a
host-only package without Config.in symbol.

Signed-off-by: Carlos Santos <casantos@datacom.com.br>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

package/pkgconf/pkgconf.mk

@@ -5,7 +5,7 @@
 ################################################################################
 
 PKGCONF_VERSION = 1.5.3
-PKGCONF_SITE = https://distfiles.dereferenced.org/pkgconf/
+PKGCONF_SITE = https://distfiles.dereferenced.org/pkgconf
 PKGCONF_SOURCE = pkgconf-$(PKGCONF_VERSION).tar.xz
 PKGCONF_LICENSE = pkgconf license
 PKGCONF_LICENSE_FILES = COPYING