soup-uri: fix the scheme parsing to require alpha, not alphanumeric
soup-uri: fix the scheme parsing to require alpha, not alphanumeric

also remove an ancient comment about running the regression tests,
since it's implied everywhere now.

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