doctor: Tweak git-clean suggestion for empty dirs

git clean -f is not enough. Needs `-d` somtimes to
handle cases when we rename a dir.

Fixes #18544 and fixes #14224
chouchdb: Needs Erlang <= R15B, print workaround.

Adds an Requirement for Erlang not greater than R15B.

Closes #18548.

Signed-off-by: Samuel John <github@SamuelJohn.de>
erlang: Fix for Xcode-only (disable dtrace)