remove duplicate check for ZLIB

diff --git a/configure.ac b/configure.ac
index c003a2c71e1116ec5a26213c3c149dc1ea7891a7..38e7c7a1c4ee9c93e5306249a5914449b95d2607 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -21,9 +21,6 @@ AC_PROG_CXX
 dnl pthread
 AX_PTHREAD([], [AC_MSG_ERROR([pthread library required])])
 
-dnl check for zlib library
-AX_CHECK_ZLIB
-
 dnl Check for Geos library
 AX_LIB_GEOS
 if test "x$GEOS_VERSION" = "x"