cmake: remove warning for OpenSSL 1.1

Works fine.

build/CMakeLists.txt

@@ -324,10 +324,6 @@ endif()
 find_package ( OpenSSL REQUIRED )
 if(NOT DEFINED OPENSSL_INCLUDE_DIR)
   message(SEND_ERROR "Could not find OpenSSL. Please download and install it first!")
-else()
-  if(NOT (OPENSSL_VERSION VERSION_LESS 1.1))
-    message(WARNING "Your OpenSSL version ${OPENSSL_VERSION} >=1.1 is experimental: build with v1.0 when possible.")
-  endif()
 endif()
 
 if (WITH_UPNP)