sqlite: use new upstream file versioning convention

Upstream decided to change the file naming convention.

sqlite-amalgamation is now sqlite-autoconf

For a given version, say, 3.7.4 (W.X.Y) upstream now uses WXXYYZZ with Z
reserved for minor fix versions, all zero padded.
Thus 3.7.4 is 3070400, 3.7.4.1 would be 3070401.

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>