Revert "fixed sticky bug in sidebar"

This reverts commit f8a97a6a9bb6242cb00f2e067feac17608d5a2c5.

Conflicts:
	css/birkeland.css
Revert "made header sticky at top"

This reverts commit d96b7d5c6ac4166ce6278aa9e0952bdf03ad4900.

Conflicts:
	css/birkeland.css