Bump https-proxy-agent from 2.2.1 to 2.2.4 in /functions

Bumps [https-proxy-agent](https://github.com/TooTallNate/node-https-proxy-agent) from 2.2.1 to 2.2.4.
- [Release notes](https://github.com/TooTallNate/node-https-proxy-agent/releases)
- [Commits](https://github.com/TooTallNate/node-https-proxy-agent/compare/2.2.1...2.2.4)

Signed-off-by: dependabot[bot] <support@github.com>

functions/package-lock.json

@@ -370,14 +370,6 @@
         "negotiator": "0.6.1"
       }
     },
-    "agent-base": {
-      "version": "4.2.1",
-      "resolved": "https://registry.npmjs.org/agent-base/-/agent-base-4.2.1.tgz",
-      "integrity": "sha512-JVwXMr9nHYTUXsBFKUqhJwvlcYU/blreOEUkhNR2eXZIvwd+c+o5V4MgDPKWnMS/56awN3TRzIP+KoPn+roQtg==",
-      "requires": {
-        "es6-promisify": "^5.0.0"
-      }
-    },
     "ansi-regex": {
       "version": "2.1.1",
       "resolved": "https://registry.npmjs.org/ansi-regex/-/ansi-regex-2.1.1.tgz",
@@ -2029,12 +2021,22 @@
       "integrity": "sha512-cZdEF7r4gfRIq7ezX9J0T+kQmJNOub71dWbgAXVHDct80TKP4MCETtZQ31xyv38UwgzkWPYF/Xc0ge55dW9Z9w=="
     },
     "https-proxy-agent": {
-      "version": "2.2.1",
-      "resolved": "https://registry.npmjs.org/https-proxy-agent/-/https-proxy-agent-2.2.1.tgz",
-      "integrity": "sha512-HPCTS1LW51bcyMYbxUIOO4HEOlQ1/1qRaFWcyxvwaqUS9TY88aoEuHUY33kuAh1YhVVaDQhLZsnPd+XNARWZlQ==",
+      "version": "2.2.4",
+      "resolved": "https://registry.npmjs.org/https-proxy-agent/-/https-proxy-agent-2.2.4.tgz",
+      "integrity": "sha512-OmvfoQ53WLjtA9HeYP9RNrWMJzzAz1JGaSFr1nijg0PVR1JaD/xbJq1mdEIIlxGpXp9eSe/O2LgU9DJmTPd0Eg==",
       "requires": {
-        "agent-base": "^4.1.0",
+        "agent-base": "^4.3.0",
         "debug": "^3.1.0"
+      },
+      "dependencies": {
+        "agent-base": {
+          "version": "4.3.0",
+          "resolved": "https://registry.npmjs.org/agent-base/-/agent-base-4.3.0.tgz",
+          "integrity": "sha512-salcGninV0nPrwpGNn4VTXBb1SOuXQBiqbrNXoeizJsHrsL6ERFM2Ne3JUSBWRE6aeNJI2ROP/WEEIDUiDe3cg==",
+          "requires": {
+            "es6-promisify": "^5.0.0"
+          }
+        }
       }
     },
     "iconv-lite": {