`das` deletes more than it should

Describe the bug
When using delete a sentence on a sentence that ends with a newline, the first character of the next line is also deleted. This only happens when the cursor is not on the first non-whitespace character of the line that is being deleted.

To Reproduce
Steps to reproduce the behavior:

1. Create a file containing:

First sentence.
Second sentence.
Third sentence.

2. Put cursor on the second character of Second sentence. In this case, 'e'.
3. delete a sentence.
4. The Second sentence. and T of the third line are deleted.

First sentence.
hird sentence.

Expected behavior
Only Second sentence. should be deleted.

Environment (please complete the following information):

• Extension (VsCodeVim) version: 1.18.5
• VSCode version: 1.52.1
• OS: Windows 10 Pro

Also tested on fresh install of Visual Studio Code - Insiders

• Extension (VsCodeVim) version: 1.18.5
• VSCode version: 1.53.0-insider
• OS: Windows 10 Pro

Reproduce the issue in VSCodeVim using the reported three-line file, placing the cursor on the second character of the middle sentence before running das. Trace the sentence-motion and deletion handling from that behavior; done means only the targeted sentence is removed and the first character of the next line remains.