remove trailing semicolon from macro

[escobar-west]

According to rust-lang/rust#79813, trailing semicolons in expression macro bodies will eventually be made into a hard error. This PR is to remove the trailing semicolon.

I discovered this issue when I was running cargo check --future-imcompat-report on my binary crate which lists console_log as a dependency. Below is a snippet of the cargo output:

warning: trailing semicolon in macro used in expression position
--> /Users/victorsuriel/.cargo/registry/src/github.com-1ecc6299db9ec823/console_log-0.2.1/src/style.rs:19:83
|
19 | concat!("color: white; padding: 0 3px; background: ", $color, ";");
...
24 | trace: bg_color!("gray"),
| ----------------- in this macro invocation
|
= warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
= note: for more information, see issue #79813 rust-lang/rust#79813
= note: #[allow(semicolon_in_expressions_from_macros)] on by default
= note: this warning originates in the macro bg_color (in Nightly builds, run with -Z macro-backtrace for more info)

[erwanvivien]

Fixes #11

[iamcodemaker]

Nice work. I'll get this merged and pushed out.