refactor download function

.config/yadm/bootstrap.d/lib/helpers

@@ -5,8 +5,16 @@ download() {
     [[ $# == 0 ]] && exit 1
 
     local url="$1"
-    local suffix="${2:-"${url##*.}"}"
-    local filename="$(mktemp -t "download-XXXXXX.${suffix}")"
+    local file="${url##*/}"
+    local suffix=""
+
+    if [[ "$#" == 2 ]]; then
+        suffix=".$2"
+    elif [[ $file == *.* ]]; then
+        suffix=".${file##*.}"
+    fi
+
+    local filename="$(mktemp -t "download-XXXXXX${suffix}")"
 
     curl --location --output "${filename}" -# "${url}"