SoupSession: don't disconnect connections outside of conn_lock
SoupSession: don't disconnect connections outside of conn_lock

Always acquire conn_lock before disconnecting IDLE connections, to
avoid race conditions.

jwendell/libsoup,jwendell/libsoup,fanc999/libsoup,Distrotech/libsoup,Distrotech/libsoup,fanc999/libsoup,fanc999/libsoup,Distrotech/libsoup,Distrotech/libsoup,jwendell/libsoup,fanc999/libsoup,fanc999/libsoup,jwendell/libsoup,jwendell/libsoup,Distrotech/libsoup