Add test for issue #1441.

(cherry picked from commit ac11197)

tests/vibe.core.net.1441/dub.sdl

@@ -0,0 +1,4 @@
+name "tests"
+description "TCP disconnect task issue"
+dependency "vibe-d:core" path="../../"
+versions "VibeDefaultMain"

tests/vibe.core.net.1441/source/app.d

@@ -0,0 +1,24 @@
+import vibe.core.core;
+import vibe.core.net;
+import core.time : msecs;
+
+shared static this()
+{
+	import vibe.core.log;
+	bool done = false;
+	listenTCP(11375,(conn){
+		conn.write("foo");
+		conn.close();
+		done = true;
+	});
+
+	runTask({
+		auto conn = connectTCP("127.0.0.1", 11375);
+		conn.close();
+
+		sleep(50.msecs);
+		assert(done);
+
+		exitEventLoop();
+	});
+}