Describe the bug
White lines/bars appearing next to mj-social-element(s) when using custom icons.

To Reproduce
Steps to reproduce the behavior:

1. Grab test code from here
2. Copy outputted HTML to EmailOnAcid and preview renders.
3. Issue appears to only affect iOS devices at certain resolutions (iPhone 7 and X, iPad)

Expected behavior
Social Icons should render properly (without lines adjacent to them)

MJML environment (please complete the following information):

• OS: Windows 10
• MJML Version: 4.2.1 (latest)
• MJML tool used: MJML CLI + Visual Studio Code

Email sending environment (for rendering issues):

• N/A

Affected email clients (for rendering issues):

• Email Client: Default iOS/Outlook
• OS: iOS 10 (iPad), iOS 11 (iPhone 7/X)

Screenshots
Rendering Issue example on iPhone 7, iPhone X (default client/Outlook)
https://i.imgur.com/mqUKn3m.png
Rendering Issue example on iPad
https://i.imgur.com/CF0eSZ9.png

Additional context
I was doing some preliminary render testing and noticed this issue, however this only occurs in certain iOS clients (according to EoA). Outlook and other mobile/desktop clients render fine. I think I've found a workaround for the iPad issue by inlining a 'display: block;' on the tag, but it doesn't solve the white line issue unfortunately. I've attempted to create an mj-class with a display:block attribute but it doesn't seem to apply to the tags within mj-social.