community/go: don't die in global scope

we have tools that parse APKBUILDs in aports so we should never die from
global scope.

community/go/APKBUILD

@@ -62,7 +62,7 @@ mips)   export GOARCH="mips" GOMIPS=softfloat ;;
 mips64) export GOARCH="mips64" GOMIPS64=softfloat ;;
 mips64el) export GOARCH="mips64le" GOMIPS64=softfloat ;;
 mipsel) export GOARCH="mipsle" GOMIPS=softfloat ;;
-*)      die "Unsupported arch" ;;
+*)      export GOARCH="unsupported";;
 esac
 
 builddir="$srcdir"/go