Upgrade unbound library

These files were pulled from the 1.6.3 release tarball.

This new version builds against OpenSSL version 1.1 which will be
the default in the new Debian Stable which is due to be released
RealSoonNow (tm).

external/unbound/ac_pkg_swig.m4

@@ -103,9 +103,20 @@ AC_DEFUN([AC_PROG_SWIG],[
                         if test -z "$available_patch" ; then
                                 [available_patch=0]
                         fi
-                        if test $available_major -ne $required_major \
-                                -o $available_minor -ne $required_minor \
-                                -o $available_patch -lt $required_patch ; then
+			[badversion=0]
+			if test $available_major -lt $required_major ; then
+				[badversion=1]
+			fi
+                        if test $available_major -eq $required_major \
+                                -a $available_minor -lt $required_minor ; then
+				[badversion=1]
+			fi
+                        if test $available_major -eq $required_major \
+                                -a $available_minor -eq $required_minor \
+                                -a $available_patch -lt $required_patch ; then
+				[badversion=1]
+			fi
+			if test $badversion -eq 1 ; then
                                 AC_MSG_WARN([SWIG version >= $1 is required.  You have $swig_version.  You should look at http://www.swig.org])
                                 SWIG='echo "Error: SWIG version >= $1 is required.  You have '"$swig_version"'.  You should look at http://www.swig.org" ; false'
                         else