Fix incorrect shift in mysqlnd_wireprotocol

This one looks like a genuine bug: We're shifting a uint16_t by
16 bits. On x86 that likely results in no shift happening.

Author: nikic

ext/mysqlnd/mysqlnd_wireprotocol.c

@@ -420,7 +420,7 @@ php_mysqlnd_greet_read(MYSQLND_CONN_DATA * conn, void * _packet)
 		p--;
 
     	/* Additional 16 bits for server capabilities */
-		packet->server_capabilities |= uint2korr(pad_start) << 16;
+		packet->server_capabilities |= (uint32_t) uint2korr(pad_start) << 16;
 		/* And a length of the server scramble in one byte */
 		packet->authentication_plugin_data.l = uint1korr(pad_start + 2);
 		if (packet->authentication_plugin_data.l > SCRAMBLE_LENGTH) {