Overflow: hidden on lt-body-wrap interferes with visibility of bootstrap dropdown

[hefox]

Hiya,

Just updated 1.8.6 to 1.13.2, and our dropdowns stopped being visible when they pass the edge of the table

This is directly from the overflow-y: hidden on the lt-body-wrap class. Removing it, everything appears to work correctly but I am guessing it has a reason for being there.