title: Importing images with MAGMI, exclude flag is ignored after the 1st import
body: <p>I am trying to update the images of my catalog with the following CSV:</p>
  
  <pre><code>store,sku,image,small_image,thumbnail,padrao,media_gallery,media_gallery_reset
  admin,TP1501054-15-XS,+/TP1501054_15_1.jpg,/TP1501054_15_1.jpg,/TP1501054_15_1.jpg,/TP1501054_15_0.jpg,/TP1501054_15_2.jpg;,1
  </code></pre>
  
  <p>It works the first time I use it.
  From that time forward, everything works ok except the "exclude" flag. It simply ignores it, in this case, the main image is excluded from the gallery.</p>
  
  <p>If I edit the product manually and remove the gallery and re-import this CSV, the main image stays without the exclude flag.
  If I re-import the same CSV again, it enables the exclude flag.</p>
  
  <p>When I import the CSV it should respect the instructions in the file.</p>
  
  <p>Anyone can reproduce this ?
  Anyone has the solution ?</p>
  
  <p>Thanks.</p>
  
  <p>magmi v0.7.21</p>