Improving rationale on the libnss lintian overrides

debian/libnss-aad.lintian-overrides

@@ -1,6 +1,8 @@
 # The versioned library is the actual library itself, there is no link to it.
 libnss-aad: lacks-versioned-link-to-shared-library
 
-# cargo build does not allow us to directly specify the version of the shared library, so we have to
-# do it manually in the dh_auto_install step.
+# cargo build currently does not support changing the output name of libraries and the functionality
+# is still being tracked at https://github.com/rust-lang/cargo/issues/9778. Therefore, we must build
+# it with the base name (i.e. libnss_aad.so) and then manually rename it to contain the version, as
+# done in the dh_auto_install step.
 libnss-aad: shared-library-lacks-version