ConfigurationTest: Remove the unused throws clauses

Align the related code style with the sibling test methods, which are
not systematically throwing Exceptions.

Change-Id: Ie7369fc1592167d4b2545abb8ef39ea59a262d40
diff --git a/src/test/java/com/googlesource/gerrit/plugins/ratelimiter/ConfigurationTest.java b/src/test/java/com/googlesource/gerrit/plugins/ratelimiter/ConfigurationTest.java
index 89299ab..c17839d 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/ratelimiter/ConfigurationTest.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/ratelimiter/ConfigurationTest.java
@@ -49,7 +49,7 @@
   private final String groupTagName = "group";
 
   @Before
-  public void setUp() throws Exception {
+  public void setUp() {
     globalPluginConfig = new Config();
 
     when(pluginConfigFactoryMock.getGlobalPluginConfig(PLUGIN_NAME)).thenReturn(globalPluginConfig);
@@ -117,7 +117,7 @@
   }
 
   @Test
-  public void testInvalidGroup() throws Exception {
+  public void testInvalidGroup() {
     // Set a good group and a bad and ensure the good is still parsed
 
     globalPluginConfig.setInt(