fix proxyservlet response url to respect http scheme if a relative

Location header is returned.

source/net/yacy/http/servlets/UrlProxyServlet.java

@@ -184,7 +184,7 @@ public class UrlProxyServlet extends HttpServlet implements Servlet {
             if (location.startsWith("http")) {
                 location = request.getServletPath() + "?url=" + location;
             } else {
-                location = request.getServletPath() + "?url=http://" + hostwithport + "/" + location;
+                location = request.getServletPath() + "?url=" + proxyurl.getProtocol() + "://" + hostwithport + "/" + location;
             }
             response.addHeader(HeaderFramework.LOCATION, location);
         } 

source/net/yacy/http/servlets/YaCyProxyServlet.java

@@ -161,7 +161,7 @@ public class YaCyProxyServlet extends HttpServlet implements Servlet {
             if (location.startsWith("http")) {
                 location = request.getServletPath() + "?url=" + location;
             } else {
-                location = request.getServletPath() + "?url=http://" + hostwithport + "/" + location;
+                location = request.getServletPath() + "?url=" + proxyurl.getProtocol() + "://" + hostwithport + "/" + location;
             }
             response.addHeader(HeaderFramework.LOCATION, location);
         }