Fix strictQuery warning from new mongoose versions

-Suppress the "DeprecationWarning: Mongoose: the `strictQuery` option will be switched back to `false` by default in Mongoose 7" warning msg when starting the explorer and using any of the scripts that connect to mongo

lib/database.js

@@ -256,6 +256,8 @@ function init_heavy(cb) {
 module.exports = {
   // initialize DB
   connect: function(database, cb) {
+    mongoose.set('strictQuery', true);
+
     mongoose.connect(database, function(err) {
       if (err) {
         console.log('Error: Unable to connect to database: %s', database);