Add double-ended-queue dependency

See https://gitlab.com/timvisee/send/-/issues/23

package-lock.json

@@ -8246,6 +8246,11 @@
         "is-obj": "^2.0.0"
       }
     },
+    "double-ended-queue": {
+      "version": "2.1.0-0",
+      "resolved": "https://registry.npmjs.org/double-ended-queue/-/double-ended-queue-2.1.0-0.tgz",
+      "integrity": "sha1-ED01J/0xUo9AGIEwyEHv3XgmTlw="
+    },
     "duplexer": {
       "version": "0.1.2",
       "resolved": "https://registry.npmjs.org/duplexer/-/duplexer-0.1.2.tgz",

package.json

@@ -141,6 +141,7 @@
     "cldr-core": "^35.1.0",
     "configstore": "github:dannycoates/configstore#master",
     "convict": "^5.2.1",
+    "double-ended-queue": "^2.1.0-0",
     "express": "^4.17.1",
     "helmet": "^3.23.3",
     "mkdirp": "^0.5.1",