thunderbird: Fix build failure in crate *style_traits* with Rust ≥ 1.33

       Compiling style_traits v0.0.1 (/dev/shm/bee-root/thunderbird/thunderbird-60.8.0-0/source/servo/components/style_traits)
    warning: use of deprecated item 'std::ascii::AsciiExt': use inherent methods instead
      --> servo/components/style_traits/viewport.rs:10:30
       |
    10 | #[allow(unused_imports)] use std::ascii::AsciiExt;
       |                              ^^^^^^^^^^^^^^^^^^^^
       |
       = note: #[warn(deprecated)] on by default
    error: missing documentation for macro
       --> servo/components/style_traits/values.rs:139:1
        |
    139 | macro_rules! serialize_function {
        | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        |
    note: lint level defined here
       --> servo/components/style_traits/lib.rs:12:22
        |
    12  | #![deny(unsafe_code, missing_docs)]
        |                      ^^^^^^^^^^^^

    error: missing documentation for macro
       --> servo/components/style_traits/values.rs:408:1
        |
    408 | macro_rules! define_css_keyword_enum {
        | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

    error: aborting due to 2 previous errors

    error: Could not compile `style_traits`.

[1]: https://bugzilla.mozilla.org/show_bug.cgi?id=1519629

thunderbird.be0

@@ -10,6 +10,7 @@ SRCURL[0]="https://ftp.mozilla.org/pub/thunderbird/releases/${PKGVERSION}/source
 
 mee_patch() {
     start_cmd sed -i -e '/#!\[deny(missing_docs)\]/d' ${S}/servo/components/style/lib.rs
+    start_cmd sed -i -e 's/#!\[deny(unsafe_code, missing_docs)\]/#!\[deny(unsafe_code)\]/g' ${S}/servo/components/style_traits/lib.rs
 }
 
 mee_configure() {