Fixed typo in NodeProperties

src/main/java/it/inaf/oats/vospace/datamodel/NodeProperties.java

@@ -23,7 +23,7 @@ public abstract class NodeProperties {
     public static final String GROUP_WRITE_URI = "ivo://ivoa.net/vospace/core#groupwrite";  // the list of groups which can read and write to this resource  delimiter-separated 
     public static final String IDENTIFIER_URI = "ivo://ivoa.net/vospace/core#identifier";  // an unambiguous reference to the resource within a given context
     public static final String LANGUAGE_URI = "ivo://ivoa.net/vospace/core#language";    // a language of the resource    
-    public static final String CORE_URI = "ivo://ivoa.net/vospace/core#length";      // the length or size of a resource      
+    public static final String LENGTH_URI = "ivo://ivoa.net/vospace/core#length";      // the length or size of a resource      
     public static final String MODIFICATION_TIME_URI = "ivo://ivoa.net/vospace/core#mtime";       // the data modification time    
     public static final String PUBLIC_READ_URI = "ivo://ivoa.net/vospace/core#publicread";  // whether this resource is world readable
     public static final String PUBLISHER_URI = "ivo://ivoa.net/vospace/core#publisher";   // an entity responsible for making the resource available