Silence warnings from ignored Result values

For a few of the locations where error handling is done correctly this
does the right thing.  For most other places it gracefully ignores any
issues which is what the original code did as well.  Errors are
already logged by the called functions in those cases.

src/dc_contact.rs

@@ -421,7 +421,8 @@ pub fn dc_add_or_lookup_contact(
                     },
                     row_id
                 ],
-            );
+            )
+            .ok();
 
             if update_name {
                 sql::execute(
@@ -429,7 +430,7 @@ pub fn dc_add_or_lookup_contact(
                     &context.sql,
                     "UPDATE chats SET name=? WHERE type=? AND id IN(SELECT chat_id FROM chats_contacts WHERE contact_id=?);",
                     params![to_string(name), 100, row_id]
-                );
+                ).ok();
             }
             unsafe { *sth_modified = 1 };
         }