add annotation

Author: knguyen99

src/com/inet/gradle/setup/msi/Msi.java

@@ -636,6 +636,7 @@ public void setExternalSignTool( Closure<?> externalSignTool ) {
      *
      * @return closure the data for signing
      */
+    @Input
     public Closure<?> getExternalSignTool() {
         return externalSignTool;
     }