Update dependency nconf to ^0.13.0

Author: renovate[bot]

packages/config/package.json

@@ -30,6 +30,6 @@
   },
   "dependencies": {
     "@tryghost/root-utils": "^0.3.33",
-    "nconf": "^0.12.0"
+    "nconf": "^0.13.0"
   }
 }

yarn.lock

@@ -7381,10 +7381,10 @@ natural-compare@^1.4.0:
   resolved "https://registry.yarnpkg.com/natural-compare/-/natural-compare-1.4.0.tgz#4abebfeed7541f2c27acfb29bdbbd15c8d5ba4f7"
   integrity sha512-OWND8ei3VtNC9h7V60qff3SVobHr996CTwgxubgyQYEpg290h9J0buyECNNJexkFm5sOajh5G116RYA1c8ZMSw==
 
-nconf@^0.12.0:
-  version "0.12.1"
-  resolved "https://registry.yarnpkg.com/nconf/-/nconf-0.12.1.tgz#b0b91d2e32dc588fad19ac8bc5245e7472ebb4b9"
-  integrity sha512-p2cfF+B3XXacQdswUYWZ0w6Vld0832A/tuqjLBu3H1sfUcby4N2oVbGhyuCkZv+t3iY3aiFEj7gZGqax9Q2c1w==
+nconf@^0.13.0:
+  version "0.13.0"
+  resolved "https://registry.yarnpkg.com/nconf/-/nconf-0.13.0.tgz#5a1c8d4376da06236ed5f3e38774b1cf62a19525"
+  integrity sha512-hJ/u2xCpA663h6xyOiztx3y+lg9eU0rdkwJ+c4FtiHo2g/gB0sjXtW31yTdMLWLOIj1gL2FcJMwfOqouuUK/Wg==
   dependencies:
     async "^3.0.0"
     ini "^2.0.0"