Startup won't hang even if a new version is available.

The same kind of dialog is displayed when a new version is available
and it should have similar increased timeout guard.

main.applescript

@@ -87,18 +87,21 @@ on run
 
 	-- Version check might fail, so guard against it.
 	try
-		if this_is_latest_version() then
-			logger("Update check: This Jenkins.app is the latest version")
-		else
-			logger("Update check: There is a newer Jenkins.app available")
-			display dialog "A newer version of Jenkins.app is available. Would you like to update?" & return & "(Automatic startup in 15 seconds.)" with title "Jenkins" with icon path_to_icon buttons {"Maybe later", "Update now"} default button "Update now" giving up after 15
-			if button returned of the result is equal to "Update now" then
-				open location "https://github.com/stisti/jenkins-app/downloads"
-				quit
-				(* To force quit to happen without continuing to the end of the handler, use the return statement to immediately return from handler. *)
-				return
+		activate
+		with timeout of 300 seconds
+			if this_is_latest_version() then
+				logger("Update check: This Jenkins.app is the latest version")
+			else
+				logger("Update check: There is a newer Jenkins.app available")
+				display dialog "A newer version of Jenkins.app is available. Would you like to update?" & return & "(Automatic startup in 15 seconds.)" with title "Jenkins" with icon path_to_icon buttons {"Maybe later", "Update now"} default button "Update now" giving up after 15
+				if button returned of the result is equal to "Update now" then
+					open location "https://github.com/stisti/jenkins-app/downloads"
+					quit
+					(* To force quit to happen without continuing to the end of the handler, use the return statement to immediately return from handler. *)
+					return
+				end if
 			end if
-		end if
+		end timeout
 	end try
 
 	tell application "Finder"