look, another reason to hate google: fuchsia's triplets confuse the hell out of poor mozconfig

meanwhile, make -foxkit- more important than -unknown-

--- thunderbird-60.2.1/build/moz.configure/rust.configure.old	2018-10-01 14:51:04.000000000 +0000
+++ thunderbird-60.2.1/build/moz.configure/rust.configure	2018-10-11 23:13:15.370000000 +0000
@@ -119,9 +119,13 @@
     ambiguous = set()
     per_raw_os = {}
     for t in out:
+        if 'fuchsia' in t: continue
         t = split_triplet(t, allow_unknown=True)
         key = (t.cpu, t.endianness, t.os)
         if key in per_os:
+            # hax to allow Adélie toolchains to work
+            if 'foxkit' in per_os[key].alias:
+                continue
             previous = per_os[key]
             per_raw_os[(previous.cpu, previous.endianness,
                         previous.raw_os)] = previous