Added missing constructor type for AbstractTextWidget.

Author: kevzlou7979

gwt-material/src/main/java/gwt/material/design/client/base/AbstractTextWidget.java

@@ -40,6 +40,10 @@ protected AbstractTextWidget(Element element) {
         super(element);
     }
 
+    protected AbstractTextWidget(Element element, String... initialClasses) {
+        super(element, initialClasses);
+    }
+
     @Override
     public String getValue() {
         return SafeHtmlUtils.fromString(getElement().getInnerText()).asString();