Issue Summary

When you use the code snippet macro inside any third party Macro there will be a JS script error stating:

"An embedded page at aura.cloudanvil.net says
SyntaxHighlighter
Can't find brush for: plain"

This is reproducible on Data Center: (not tested yet)

Steps to Reproduce

1. Created a new page.
2. Insterted the Aura - Panel Macro. (Or any other macro from third-party that allows you to insert the Code snippet macro inside)
3. Inserted the code snippet macro inside the Aura - Panel Macro.
4. Insert text inside the code block macro.
5. Selected NONE as a language option, (or any other language really, it doesn't matter)
6. Published the page.

Expected Results

Code snnipet macro should display the text, no error should be observed, and syntax h

Actual Results

The below exception is thrown in the console.log file:

ReferenceError: SyntaxHighlighter is not defined
at com.atlassian.confluence.ext.newcode-macro-plugin:syntaxhighlighter-brushes.js?assetVersion=1000.0.0-ff6d4d2adf1c&externals={_}local-default{_}:125:13
at com.atlassian.confluence.ext.newcode-macro-plugin:syntaxhighlighter-brushes.js?assetVersion=1000.0.0-ff6d4d2adf1c&externals={_}local-default{_}:125:1079
WRMCB @ com.atlassian.confluence.ext.newcode-macro-plugin:syntaxhighlighter-brushes.js?assetVersion=1000.0.0-ff6d4d2adf1c&externals={_}local-default{_}:1
(anonymous) @ com.atlassian.confluence.ext.newcode-macro-plugin:syntaxhighlighter-brushes.js?assetVersion=1000.0.0-ff6d4d2adf1c&externals={_}local-default{_}:126

Workaround

Insert code snippet macro outside the third-party Macro or any other Macros that could cause this issue.