cmake/TryNetCDF_DAP.c check outdated

I don't know when the change occurred in **${NetCDF_C_INCLUDE_DIR}/includes/netcdf_meta.h** but at least as far back as NetCDF-C v4.5.0, '**NC_HAS_DAP**' was replaced by '**NC_HAS_DAP2**' and '**NC_HAS_DAP4**'. The code in **cmake/TryNetCDF_DAP.c** causes linking with any semi-recent, DAP enabled version of NetCDF to fail because the search for curl and subsequent addition to the _**NetCDF_C_Libraries**_ list is omitted. I believe line 8 of **cmake/TryNetCDF_DAP.c** should read:

`#if NC_HAS_DAP==1 || NC_HAS_DAP2==1 || NC_HAS_DAP4==1`