Don't println! in Drop (see rust-lang/rust#29488)

Author: mleduque

couchbase-lite/src/replicator.rs

@@ -23,13 +23,6 @@ struct CallContext {
     after_pull_ctx: *mut c_void,
 }
 
-impl Drop for CallContext {
-    fn drop(&mut self) {
-        println!("CallContext.drop()");
-        // fields are dropped implicitely (I think)
-    }
-}
-
 pub(crate) struct Replicator {
     inner: NonNull<C4Replicator>,
     c_callback_on_status_changed: C4ReplicatorStatusChangedCallback,
@@ -45,7 +38,6 @@ unsafe impl Send for Replicator {}
 
 impl Drop for Replicator {
     fn drop(&mut self) {
-        println!("Replicator.drop()");
         unsafe {
             c4repl_free(self.inner.as_ptr());
             (self.free_callback_f)(self.callback_context.as_ptr());