Added comments regarding HTTPS proxies

Author: tomdesair

src/main/java/me/desair/tus/server/creation/CreationPostRequestHandler.java

@@ -40,6 +40,9 @@ public void process(HttpMethod method, TusServletRequest servletRequest,
 
         //We've already validated that the current request URL matches our upload URL so we can safely use it.
         String uploadURI = servletRequest.getRequestURI();
+
+        //It's important to return relative UPLOAD URLs in the Location header in order to support HTTPS proxies
+        //that sit in front of the web app
         String url = uploadURI + (StringUtils.endsWith(uploadURI, "/") ? "" : "/") + info.getId();
         servletResponse.setHeader(HttpHeader.LOCATION, url);
         servletResponse.setStatus(HttpServletResponse.SC_CREATED);

src/test/java/me/desair/tus/server/creation/ITCreationExtension.java

@@ -31,6 +31,9 @@
 public class ITCreationExtension extends AbstractTusExtensionIntegrationTest {
 
     private static final String UPLOAD_URI = "/test/upload";
+
+    //It's important to return relative UPLOAD URLs in the Location header in order to support HTTPS proxies
+    //that sit in front of the web app
     private static final String UPLOAD_URL = UPLOAD_URI + "/";
 
     private UUID id;