Use constants from VeraPDFMeta

Author: MaximPlusov

validation-model/src/main/java/org/verapdf/gf/model/GFModelParser.java

@@ -208,10 +208,10 @@ private static PDFAFlavour detectPDFAFlavour(VeraPDFMeta veraPDFMeta) {
 
 	private static List<PDFAFlavour> detectWTPDFFlavour(VeraPDFMeta veraPDFMeta) {
 		List<PDFAFlavour> wtpdfFlavours = new LinkedList<>();
-		if (veraPDFMeta.containsDeclaration("http://pdfa.org/declarations/wtpdf#accessibility1.0")) {
+		if (veraPDFMeta.containsDeclaration(VeraPDFMeta.WTPDF_ACCESSIBILITY_DECLARATION)) {
 			wtpdfFlavours.add(PDFAFlavour.WTPDF_1_0_ACCESSIBILITY);
 		}
-		if (veraPDFMeta.containsDeclaration("http://pdfa.org/declarations/wtpdf#reuse1.0")) {
+		if (veraPDFMeta.containsDeclaration(VeraPDFMeta.WTPDF_REUSE_DECLARATION)) {
 			wtpdfFlavours.add(PDFAFlavour.WTPDF_1_0_REUSE);
 		}
 		return wtpdfFlavours;