Use noinst_HEADERS instead of EXTRA_DIST for wslay public headers.

deps/wslay/lib/includes/Makefile.am

@@ -20,4 +20,4 @@
 # LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-EXTRA_DIST = wslay/wslay.h wslay/wslayver.h
+noinst_HEADERS = wslay/wslay.h wslay/wslayver.h