title: SpringBoot's @MultipartConfig maxFileSize not taking effect
body: <p>I have a controller with a <code>MultipartConfig</code> annotation (a snippet of which is show below):</p>
  
  <pre><code>@RestController
  @RequestMapping("packages")
  @MultipartConfig(maxFileSize = 1024*1024*1024, maxRequestSize = 1024*1024*1024)
  public class PackagesController
  {
      @RequestMapping(method = RequestMethod.POST)
      public String create(@RequestParam("package") MultipartFile uploadedPackage)
      {
          // do stuff to the file
          return "create";
      }
  }
  </code></pre>
  
  <p>When I upload a file to this endpoint, though, it appears to be using the default multipart config values:</p>
  
  <pre><code>Caused by: org.apache.tomcat.util.http.fileupload.FileUploadBase$FileSizeLimitExceededException: The field package exceeds its maximum permitted size of 1048576 bytes.
      at org.apache.tomcat.util.http.fileupload.FileUploadBase$FileItemIteratorImpl$FileItemStreamImpl$1.raiseError(FileUploadBase.java:633) ~[tomcat-embed-core-8.0.32.jar:8.0.32]
      at org.apache.tomcat.util.http.fileupload.util.LimitedInputStream.checkLimit(LimitedInputStream.java:76) ~[tomcat-embed-core-8.0.32.jar:8.0.32]
      at org.apache.tomcat.util.http.fileupload.util.LimitedInputStream.read(LimitedInputStream.java:135) ~[tomcat-embed-core-8.0.32.jar:8.0.32]
      at java.io.FilterInputStream.read(FilterInputStream.java:107) ~[na:1.8.0_45]
      at org.apache.tomcat.util.http.fileupload.util.Streams.copy(Streams.java:98) ~[tomcat-embed-core-8.0.32.jar:8.0.32]
      at org.apache.tomcat.util.http.fileupload.util.Streams.copy(Streams.java:68) ~[tomcat-embed-core-8.0.32.jar:8.0.32]
      at org.apache.tomcat.util.http.fileupload.FileUploadBase.parseRequest(FileUploadBase.java:293) ~[tomcat-embed-core-8.0.32.jar:8.0.32]
      at org.apache.catalina.connector.Request.parseParts(Request.java:2776) ~[tomcat-embed-core-8.0.32.jar:8.0.32]
      ... 30 common frames omitted
  </code></pre>
  
  <p>My application looks like this: </p>
  
  <pre><code>@SpringBootApplication
  public class Application {
  
      public static void main(String[] args) {
          ApplicationContext ctx = SpringApplication.run(Application.class, args);
      }
  
  }
  </code></pre>
  
  <p>Is there something I'm missing that allows the <code>@MultipartConfig</code> annotation to take effect?</p>