Describe the bug
Related to #325 in that escapes are wrongly saved into the file under specific circumstances. In this case, it appears to happen only when the line begins with a colon (I use markdown with vimwiki and tags start with a colon)

To Reproduce
Steps to reproduce the behavior:

1. Create new .md file from the web interface
2. Input the following text:

test:
:test:
:test:test:
    :test:

3. Close the document
4. Download the document and open in a text edit
5. Observe that lines 2 and 3 now begin with a slash:

test:
\:test:
\:test:test:
    :test:

Expected behavior
Preserved documents

Client details:

• OS: Arch Linux
• Browser: Firefox
• Version: Latest
• Device: Laptop