Always use HTTPS sources for NPM modules in yarn.lock

Part of https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/28445Signed-off-by: Takuya Noguchi <takninnovationresearch@gmail.com>

yarn.lock

@@ -4909,7 +4909,7 @@ exports-loader@^0.7.0:
 
 express@^4.16.2, express@^4.16.3:
   version "4.16.3"
-  resolved "http://registry.npmjs.org/express/-/express-4.16.3.tgz#6af8a502350db3246ecc4becf6b5a34d22f7ed53"
+  resolved "https://registry.npmjs.org/express/-/express-4.16.3.tgz#6af8a502350db3246ecc4becf6b5a34d22f7ed53"
   integrity sha1-avilAjUNsyRuzEvs9rWjTSL37VM=
   dependencies:
     accepts "~1.3.5"
@@ -8304,7 +8304,7 @@ mixin-deep@^1.2.0:
 
 mkdirp@0.5.x, mkdirp@0.x, "mkdirp@>=0.5 0", mkdirp@^0.5.0, mkdirp@^0.5.1, mkdirp@~0.5.0, mkdirp@~0.5.1:
   version "0.5.1"
-  resolved "http://registry.npmjs.org/mkdirp/-/mkdirp-0.5.1.tgz#30057438eac6cf7f8c4767f38648d6697d75c903"
+  resolved "https://registry.npmjs.org/mkdirp/-/mkdirp-0.5.1.tgz#30057438eac6cf7f8c4767f38648d6697d75c903"
   integrity sha1-MAV0OOrGz3+MR2fzhkjWaX11yQM=
   dependencies:
     minimist "0.0.8"