Remove inline styles from parsed blockquote tag
css_styled_content's lib.parseFunc_RTE has the following rule:
externalBlocks.blockquote.callRecursive.tagStdWrap.HTMLparser.tags.blockquote.overrideAttribs = style="margin-bottom:0;margin-top:0;"
I don't know the intention of this rule (it's there since at least 20041) but it ruins my output as it removes my attributes (such as class) from blockquote tags and sets the inline styles instead - those should be avoided anyway.
So my suggestion is to simply remove this rule.