make gdal test depend on using gdal

Author: jedwards4b

tests/cunit/Makefile.am

@@ -20,8 +20,10 @@ test_darray_async test_darray_async_many test_darray_2sync		\
 test_async_multicomp test_async_multi2 test_async_manyproc		\
 test_darray_fill test_decomp_frame test_perf2 test_async_perf		\
 test_darray_vard test_async_1d test_darray_append test_simple           \
-test_darray_lossycompress test_gdal
-
+test_darray_lossycompress
+if PIO_USE_GDAL
+  check_PROGRAMS += test_gdal
+endif
 if RUN_TESTS
 # Tests will run from a bash script.
 TESTS = run_tests.sh