Windows builds reqquire Mosquitto (for MQTT) and OpsenSSL DLLs now

Technically, the OpenSSL DLLs aren't used right now because I have TLS support
disabled in the 'develop' branch version of mosquitto.dll v2.1.0 that I have
in the repo, but that should soon change.

exec/testbuild.js

@@ -127,6 +127,7 @@ var win32_dist
 		"3rdp/win32.release/nspr/bin/*.dll",
 		"3rdp/win32.release/cryptlib/bin/*.dll",
 		"3rdp/win32.release/libarchive/bin/*.dll",
+		"3rdp/win32.release/mosquitto/bin/*.dll",
 		"3rdp/win32.release/zlib/bin/*.dll",
 		"s:/sbbs/exec/dosxtrn.exe"
 	];