Bump lodash from 4.17.15 to 4.17.21 in /server

Bumps [lodash](https://github.com/lodash/lodash) from 4.17.15 to 4.17.21.
- [Release notes](https://github.com/lodash/lodash/releases)
- [Commits](lodash/lodash@4.17.15...4.17.21)

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

Author: dependabot[bot]

server/package.json

@@ -47,6 +47,6 @@
     "cookie-parser": "^1.4.4",
     "express": "^4.16.3",
     "geolib": "^2.0.24",
-    "lodash": "^4.17.10"
+    "lodash": "^4.17.21"
   }
 }

server/yarn.lock

@@ -2511,11 +2511,16 @@ lodash.unescape@4.0.1:
   resolved "https://registry.yarnpkg.com/lodash.unescape/-/lodash.unescape-4.0.1.tgz#bf2249886ce514cda112fae9218cdc065211fc9c"
   integrity sha1-vyJJiGzlFM2hEvrpIYzcBlIR/Jw=
 
-lodash@4.17.15, lodash@^4.17.10, lodash@^4.17.11, lodash@^4.17.12, lodash@^4.17.14:
+lodash@4.17.15:
   version "4.17.15"
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.15.tgz#b447f6670a0455bbfeedd11392eff330ea097548"
   integrity sha512-8xOcRHvCjnocdS5cpwXQXVzmmh5e5+saE2QGoeQmbKmRS6J3VQppPOIt0MnmE+4xlZoumy0GPG0D0MVIQbNA1A==
 
+lodash@^4.17.10, lodash@^4.17.11, lodash@^4.17.12, lodash@^4.17.14, lodash@^4.17.21:
+  version "4.17.21"
+  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.21.tgz#679591c564c3bffaae8454cf0b3df370c3d6911c"
+  integrity sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg==
+
 log-symbols@2.2.0:
   version "2.2.0"
   resolved "https://registry.yarnpkg.com/log-symbols/-/log-symbols-2.2.0.tgz#5740e1c5d6f0dfda4ad9323b5332107ef6b4c40a"