Remove unnecessary runtime dependencies.

`knotc status configure` shows summary from the configure script,
but that contains also references like include paths.
Filter these at least in a crude way (whole lines).
--- a/configure.ac
+++ b/configure.ac
@@ -947,3 +947,3 @@
 
-result_msg_esc=$(echo -n "    Configure:$filtered_config_params\n$result_msg_base" | sed '$!s/$/\\n/' | tr -d '\n')
+result_msg_esc=$(echo -n "    Configure:$filtered_config_params\n$result_msg_base" | grep -Fv "$NIX_STORE" | sed '$!s/$/\\n/' | tr -d '\n')