Descriptions from exif data with only whitespeces are considered empty

I noticed that pictures taken with Ubuntu-Touch have whitespace in one of the fields
This should just be ignored imo

lib/pleroma/upload/filter/exiftool/read_description.ex

@@ -35,6 +35,8 @@ defp read_when_empty(_, file, tag) do
       {tag_content, 0} =
         System.cmd("exiftool", ["-b", "-s3", tag, file], stderr_to_stdout: true, parallelism: true)
 
+      tag_content = String.trim(tag_content)
+
       if tag_content != "" and
            String.length(tag_content) <=
              Pleroma.Config.get([:instance, :description_limit]),

test/pleroma/upload/filter/exiftool/read_description_test.exs

@@ -83,6 +83,25 @@ test "Return nil when image description from EXIF data exceeds the maximum lengt
              {:ok, :filtered, @uploads}
   end
 
+  test "Ignores content with only whitespace" do
+    uploads = %Pleroma.Upload{
+      name: "non-existant.jpg",
+      content_type: "image/jpeg",
+      path:
+        Path.absname(
+          "test/fixtures/image_with_imagedescription_and_caption-abstract_whitespaces.jpg"
+        ),
+      tempfile:
+        Path.absname(
+          "test/fixtures/image_with_imagedescription_and_caption-abstract_whitespaces.jpg"
+        ),
+      description: nil
+    }
+
+    assert Filter.Exiftool.ReadDescription.filter(uploads) ==
+             {:ok, :filtered, uploads}
+  end
+
   test "Return nil when image description from EXIF data can't be read" do
     uploads = %Pleroma.Upload{
       name: "non-existant.jpg",