Collection contents with an eadid beginning with a number don't load properly

[mxMiles]

We've noticed that collections with an EADID beginning with a number do not load properly in the content view. The pluses don't work--nothing shows up when you click them.

Live example:
https://archives.library.wcsu.edu/caoSearch/catalog/1970_35_1 (though we're going to be quick-fixing this on our end soon by changing Litchfield's eadids)

I think this is related to #895 in that it's caused by the same bootstrap limitation-- "Bootstrap collapse functionality apparently depends on the id of the collapsed element not beginning with a number."