build: enable sdbus++ common.hpp output

This repository is [incorrectly] not using the sdbus++-gen-meson,
but instead is hand-rolling the sdbus++ calls.  The newest version
of sdbus++ adds a dependency between `server.hpp` and `common.hpp`,
so add the invocations as necessary.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I250cb0caa5ef6ab0e63f4e8cd66b8ae4f7c85500
diff --git a/meson.build b/meson.build
index aee5da1..3aa2991 100644
--- a/meson.build
+++ b/meson.build
@@ -165,6 +165,7 @@
         'dump_serialize.cpp',
         'elog_watch.cpp',
         errors_map_hpp,
+        common_hpp,
         server_hpp,
         server_cpp,
         'watch.cpp',