Use throw in catch block

Change-Id: I5d77ce45ef25e034b4f3c1b10fcd437665e1e3f1
diff --git a/src/main/java/com/googlesource/gerrit/plugins/web/WebPluginScanner.java b/src/main/java/com/googlesource/gerrit/plugins/web/WebPluginScanner.java
index 2a8815c..130750a 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/web/WebPluginScanner.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/web/WebPluginScanner.java
@@ -122,7 +122,7 @@
             }
           });
     } catch (IOException e) {
-      new IllegalArgumentException("Cannot scan resource files in plugin", e);
+      throw new IllegalArgumentException("Cannot scan resource files in plugin", e);
     }
     return Collections.enumeration(resourcesList);
   }