exim: security bump to 4.87.1

No features are added or removed. This release contains
just a fix for CVE-2016-9963

    - Fix CVE-2016-9963 - Info leak from DKIM.  When signing DKIM, if
      either LMTP or PRDR was used for delivery, the key could appear in
      logs.  Additionally, if the experimental feature "DSN_INFO" was used,
      it could appear in DSN messages (and be sent offsite).

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/exim/exim.hash

@@ -1,2 +1,2 @@
 # Locally calculated
-sha256	74691e0dff4d1b5d387e9c33c86f96a8f6d2adbc781c0dec9d2061a847b07dc9	exim-4.87.tar.bz2
+sha256	d4b7994c89240d2f9a9fcd7a2dffa4b72f14379001a24266f4dbb0fbe5131514	exim-4.87.1.tar.bz2

package/exim/exim.mk

@@ -4,9 +4,9 @@
 #
 ################################################################################
 
-EXIM_VERSION = 4.87
+EXIM_VERSION = 4.87.1
 EXIM_SOURCE = exim-$(EXIM_VERSION).tar.bz2
-EXIM_SITE = ftp://ftp.exim.org/pub/exim/exim4
+EXIM_SITE = ftp://ftp.exim.org/pub/exim/exim4/old
 EXIM_LICENSE = GPLv2+
 EXIM_LICENSE_FILES = LICENCE
 EXIM_DEPENDENCIES = pcre berkeleydb host-pkgconf