trim_left_matches (deprecated) => trim_start_matches

[kevinkassimo]

For this on Rust 1.33 (trim_start_matches is added on Rust 1.30 so I would assume this patch would build):

error: use of deprecated item 'core::str::<impl str>::trim_left_matches': superseded by `trim_start_matches`
  --> ../../src/resolve_addr.rs:88:15
   |
88 |     let p = p.trim_left_matches(':');
   |               ^^^^^^^^^^^^^^^^^
   |
   = note: `-D deprecated` implied by `-D warnings`

[ry]

LGTM