net.server_epoll: Handle LuaSec wantread/wantwrite conditions before callbacks (fixes #1333)

This prevents the :set(true) call from resuming a connection that was
paused in the onincoming callback.

net/server_epoll.lua

@@ -355,15 +355,18 @@ function interface:onreadable()
 		self:onconnect();
 		self:on("incoming", data);
 	else
-		if partial and partial ~= "" then
-			self:onconnect();
-			self:on("incoming", partial, err);
-		end
 		if err == "wantread" then
 			self:set(true, nil);
+			err = "timeout";
 		elseif err == "wantwrite" then
 			self:set(nil, true);
-		elseif err ~= "timeout" then
+			err = "timeout";
+		end
+		if partial and partial ~= "" then
+			self:onconnect();
+			self:on("incoming", partial, err);
+		end
+		if err ~= "timeout" then
 			self:on("disconnect", err);
 			self:destroy()
 			return;