build: Enable compression libs also in automatic check mode

The code setting the compression macros when found was only acting when
explicitly enabling the compression libraries.

debian/changelog

@@ -12,6 +12,8 @@ dpkg (1.18.16) UNRELEASED; urgency=medium
     - Update dpkg-parsechangelog parser options. The options specific to
       the changelog parser program did not get updated when the parser got
       switched to be a perl module. Missed in dpkg 1.18.8.
+  * Build system:
+    - Enable compression libs also in automatic check mode in configure.
 
   [ Updated scripts translations ]
   * German (Helge Kreutzmann).

m4/dpkg-libs.m4

@@ -43,7 +43,7 @@ AC_DEFUN([DPKG_WITH_COMPRESS_LIB], [
       ])
     ])
 
-    AS_IF([test "x$with_lib$1" = "xyes"], [
+    AS_IF([test "x$with_lib$1" != "xno"], [
       AS_IF([test "x$have_lib$1" = "xyes"], [
         AC_DEFINE([WITH_LIB]AS_TR_CPP($1), 1,
           [Define to 1 to use $1 library rather than console tool])