update v2 screenshot image.

v2/index.html

@@ -40,10 +40,10 @@
 			<!-- Carousel items -->
 			<div class="carousel-inner">
 				<div class="active item">
-					<img src="https://github.com/oldj/SwitchHosts/blob/master/screenshots/7.png?raw=true" alt="截图"/>
+					<img src="images/7.png" alt="截图"/>
 				</div>
 				<div class="item">
-					<img src="https://github.com/oldj/SwitchHosts/blob/master/screenshots/6.png?raw=true" alt="截图"/>
+					<img src="images/6.png" alt="截图"/>
 				</div>
 			</div>
 			<!-- Carousel nav -->