Update shaderblow.adoc

Correct usage error.

src/docs/asciidoc/sdk/plugin/shaderblow.adoc

@@ -468,6 +468,7 @@ if (crs.getClosestCollision() != null) {
 
 // Register a hit
 this.forceShieldControl.registerHit(crs.getClosestCollision().getContactPoint());
+}
 ----
 
 link:https://github.com/jMonkeyEngine-Contributions/shaderblowlib/blob/master/ShaderBlow/test-src/com/shaderblow/test/forceshield/TestShield.java[TestCase]