fix(solutions): incorrect tabItem value

Author: wingkwong

solutions/1700-1799/1791-find-center-of-star-graph-easy.md

@@ -67,7 +67,7 @@ class Solution:
 
 </TabItem>
 
-<TabItem value="py" label="Java">
+<TabItem value="java" label="Java">
 <SolutionAuthor name="@adlet_lee"/>
 
 ```java