removed some code smells

src/main/java/ninja/javafx/smartcsv/validation/checker/GroovyValidation.java

@@ -37,11 +37,11 @@ import org.codehaus.groovy.control.CompilationFailedException;
 public class GroovyValidation extends EmptyValueIsValid {
 
     private String groovyScript;
-    private GroovyShell shell = new GroovyShell();
     private Script script;
 
     public GroovyValidation(String groovyScript) {
         this.groovyScript = groovyScript;
+        GroovyShell shell = new GroovyShell();
         script = shell.parse(groovyScript);
     }
 

src/main/java/ninja/javafx/smartcsv/validation/checker/UuidValidation.java

@@ -34,6 +34,7 @@ import java.util.UUID;
  */
 public class UuidValidation extends EmptyValueIsValid {
 
+    @SuppressWarnings("ResultOfMethodCallIgnored")
     @Override
     public void check(int row, String value, ValidationError error) {
         try {