Fix nlohmann dependency for bmcweb

- nlohmann-json is treated as header dependency for meson,
  and is already exists, but for some reason if nlohmann-json
  dependency is not found in the host system, then we trigger
  the wrap dependency system for nlohmann-json through which
  we download the source code,and add header to the includes.

- But as that is not added as an explicit dependency, bmcweb
  might fail to locate the downloaded header files, this commit
  would fix that behaviour.

Tested By:

- removed json-devel(in fedora), and tried compiling bmcweb and
  it successfully compiles with this patchset.

Signed-off-by: Manojkiran Eda <manojkiran.eda@gmail.com>
Change-Id: Id98b7320c326fa41485caeb2e1b99a43dbfcef1f
diff --git a/meson.build b/meson.build
index e68bc28..bf347fa 100644
--- a/meson.build
+++ b/meson.build
@@ -370,7 +370,7 @@
             include_directories : incdir,
             dependencies: [
                               boost, boost_url, pam, atomic, sdbusplus, openssl,
-                              tinyxml, systemd, zlib
+                              tinyxml, systemd, zlib, nlohmann_json
                           ],
             install: true,
             install_dir:bindir)
@@ -382,7 +382,7 @@
                 include_directories : incdir,
                 install_dir: bindir,
                 dependencies: [
-                                boost, boost_url, gtest,openssl,gmock
+                                boost, boost_url, gtest,openssl,gmock,nlohmann_json
                               ]))
   endforeach
 endif