Fiz get_zsync() so it correctly falls back to web_get()

quickget

@@ -639,12 +639,9 @@ function web_get() {
 
 function zsync_get() {
     local DIR="${2}"
-    local FILE=""
+    local FILE="${1##*/}"
     local OUT=""
     local URL="${1}"
-    local ZS=""
-
-    FILE="${URL##*/}"
 
     if command -v zsync &>/dev/null; then
         if [ -n "${3}" ]; then
@@ -668,7 +665,11 @@ function zsync_get() {
         fi
     else
         echo "INFO: zsync not found, falling back to wget/aria2c"
-      web_get "${ISO}" "${DIR}"
+        if [ -n "${3}" ]; then
+            web_get "${1}" "${2}" "${3}"
+        else
+            web_get "${1}" "${2}"
+        fi
     fi
 }