Auto merge of #6916 - matthiaskrgr:single_largest, r=alexcrichton
crate download: don't print that a crate was the largest download if it was the only download
before:
Updating crates.io index
Downloaded procs v0.8.4
Downloaded 1 crates (1.1 MB) in 2.90s (largest was `procs` at 1.1 MB)
Installing procs v0.8.4
after:
Updating crates.io index
Downloaded procs v0.8.4
Downloaded 1 crates (1.1 MB) in 1.50s
Installing procs v0.8.4