compile fix: define AmUriParser only once

core/AmUriParser.h

@@ -24,6 +24,8 @@
  * along with this program; if not, write to the Free Software 
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
+#ifndef _AmUriParser_h_
+#define _AmUriParser_h_
 
 #include <string>
 #include <map>
@@ -51,3 +53,5 @@ struct AmUriParser {
   void dump();
   AmUriParser() { }
 };
+
+#endif