Change TEST_DEPENDS from py-beautifulsoup448 to py-beautifulsoup

• Bump PORTREVISION for dependency change

py-beautifulsoup448 (beautifulsoup4 4.8.2) was added only for py-wagtail which
requires beautifulsoup4 >=4.8<4.9. Other ports should use py-beautifulsoup
(beautifulsoup4 4.9.3) instead.