publishToConfluence - html error when pics are referenced twice in the same adoc

**Describe the bug**
We do have a adoc file which uses the same image twice

image:image32.png[image32,width=323,height=117]
....
image:image32.png[image32,width=323,height=117]`

If we now run the publishToConfluence we get an error:

'Start getting headers
image: ./images/image13.png
image: ./images/image14.png
image: ./images/image15.png
image: ./images/image6.png
image: ./images/image7.png
image: ./images/image8.png
image: ./images/image9.png
image: ./images/image10.png
image: ./images/image27.png
image: ./images/image28.png
image: ./images/image29.png
image: ./images/image30.png
image: ./images/image31.png
image: ./images/image32.png
image: ./images/image32.png
image: ./images/image33.png
image: ./images/image34.png
image: ./images/image35.png
image: ./images/image36.png
image: ./images/image37.png
image: ./images/image38.png
image: ./images/image39.png
...
* What went wrong:
Execution failed for task :docToolchain:publishToConfluence.
> groovyx.net.http.HttpResponseException: status code: 400

If I remove one of the usages it works fine.

Start getting headers
image: ./images/ExecuteStyleIntCheck.png
image: ./images/AxiDashboard_NewFindings.png
image: ./images/image13.png
image: ./images/image14.png
image: ./images/image15.png
image: ./images/CheckSequence.drawio.png
image: ./images/image6.png
image: ./images/image7.png
image: ./images/image8.png
image: ./images/image9.png
image: ./images/image10.png
image: ./images/image27.png
image: ./images/image28.png
image: ./images/image29.png
image: ./images/image30.png
image: ./images/image31.png
image: ./images/image32.png
image: ./images/image34.png
image: ./images/image35.png
image: ./images/image36.png
image: ./images/image37.png
image: ./images/image38.png
image: ./images/image39.png
...
BUILD SUCCESSFUL in 1m 34s
2 actionable tasks: 2 executed

**To Reproduce**
Steps to reproduce the behavior:
1. create a adoc and one image
2. use to the image in the adoc twice
3. run publishToConfluence
4. See error

**Expected behavior**
I would expect that I can use a image as often as I need in one file.

**Screenshots**
If applicable, add screenshots to help explain your problem.

**Configuration**
- docToolchain version LATEST
------------------------------------------------------------
Gradle 6.7.1
------------------------------------------------------------

Build time: 2020-11-16 17:09:24 UTC
Revision: 2972ff02f3210d2ceed2f1ea880f026acfbab5c0

Kotlin: 1.3.72
Groovy: 2.5.12
Ant: Apache Ant(TM) version 1.10.8 compiled on May 10 2020
JVM: 1.8.0_362 (Red Hat, Inc. 25.362-b08)
OS: Windows 10 10.0 amd64

Start by reproducing the issue with the publishToConfluence task and an .adoc file that references the same image twice. Trace how the task processes the repeated image paths and verify the fix by confirming publication succeeds while both image uses remain in the document.

Written by the indexing model from the issue text.