Change libdl and libz checks to warnings when not found.
diff --git a/configure.in b/configure.in
index 444528c..232483d 100644
--- a/configure.in
+++ b/configure.in
@@ -143,9 +143,9 @@
CFLAGS="$CFLAGS $(pkg-config --cflags openssl)";
AC_CHECK_LIB([dl], [dlopen], [],
- [AC_MSG_FAILURE([can't find libdl])])
+ [AC_MSG_WARN([can't find libdl])])
AC_CHECK_LIB([z], [inflate], [],
- [AC_MSG_FAILURE([can't find libz])])
+ [AC_MSG_WARN([can't find libz])])
AC_CHECK_LIB([crypto], [EVP_EncryptInit], [],
[AC_MSG_FAILURE([can't find openssl >1.0.1 crypto lib])])
AC_CHECK_LIB([crypto], [EVP_aes_128_ctr], [],