widen "Number of announcements" box
widen "Number of announcements" box

test plan: the dropdown button on "number of announcements shown..."
message in "more course settings" should not obscure a double-digit
number contained in the box

fixes CNVS-33975

Change-Id: I9b2b623d251884a382bcfba9981955964851af81
Reviewed-on: https://gerrit.instructure.com/98496
Tested-by: Jenkins
Reviewed-by: James Williams  <3a5f4ed991dbfa5c9ef76ad729d240ca12f62180@instructure.com>
QA-Review: David Tan <6283e310a2278fc51bdc4fb5974f70dd9c3366b9@instructure.com>
Product-Review: Jeremy Stanley <b3f594e10a9edcf5413cf1190121d45078c62290@instructure.com>

matematikk-mooc/canvas-lms,instructure/canvas-lms,venturehive/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,djbender/canvas-lms,venturehive/canvas-lms,sfu/canvas-lms,venturehive/canvas-lms,matematikk-mooc/canvas-lms,SwinburneOnline/canvas-lms,grahamb/canvas-lms,matematikk-mooc/canvas-lms,matematikk-mooc/canvas-lms,venturehive/canvas-lms,instructure/canvas-lms,grahamb/canvas-lms,sfu/canvas-lms,SwinburneOnline/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,djbender/canvas-lms,grahamb/canvas-lms,sfu/canvas-lms,SwinburneOnline/canvas-lms,djbender/canvas-lms,grahamb/canvas-lms,djbender/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,grahamb/canvas-lms,SwinburneOnline/canvas-lms