fix compile problem regarding hwcrypto/sha.h

- https://forum.arduino.cc/t/https-webserver-with-external-library-esp32-https-server-on-esp32/912930/2
- fhessel#163
- other idea hardkernel/ODROID-GO#24 (comment)

src/HTTPConnection.hpp

@@ -6,7 +6,7 @@
 
 #include <string>
 #include <mbedtls/base64.h>
-#include <hwcrypto/sha.h>
+#include <sha/sha_parallel_engine.h>
 #include <functional>
 
 // Required for sockets