Stop passing `?dummy=/distname` in URLs

[mat]

Summary

This is an idea to fix a "caching" issue from https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=298395

Right now, fetch will be run as:

/usr/bin/fetch -Fpr  -S 20907 -o rust/crates/zeroize-1.8.2.crate https://static.crates.io/crates/zeroize/zeroize-1.8.2.crate?dummy=/rust/crates/zeroize-1.8.2.crate
/usr/bin/fetch -Fpr  -S 9153588 https://codeload.github.com/stevedekorte/io/tar.gz/2017.09.06?dummy=/stevedekorte-io-2017.09.06_GH0.tar.gz

With this patch, it changes things to:

/usr/bin/fetch -Fpr  -S 20907 -o rust/crates/zeroize-1.8.2.crate https://static.crates.io/crates/zeroize/zeroize-1.8.2.crate
/usr/bin/fetch -Fpr  -S 9153588 -o stevedekorte-io-2017.09.06_GH0.tar.gz https://codeload.github.com/stevedekorte/io/tar.gz/2017.09.06

[mat]

Fixup things and add ports that need fixing.
There are two other ports that define do-fetch and actually call do-fetch.sh biology/gatk and lang/bun, those need more fixing

[mat]

Oh, no, the two ports that actually uses do-fetch are already broken, this patch is not what breaks them.

[siva]

This is great, thanks! I'd like to see a "exp-fetch" on this. No need to build all ports, but at the very least, if we attempt to mass fetch ports and all the checksums match as before, then we can rest assured that ports will build the same way as before.