Fix select columns

Revert previous projections since select columns is using projection.

src/Jenssegers/Mongodb/Query/Builder.php

@@ -285,6 +285,11 @@ class Builder extends BaseBuilder {
                 $columns[$column] = true;
             }
 
+            // Add custom projections.
+            if ($this->projections)
+            {
+                $columns = array_merge($columns, $this->projections);
+            }
             $options = [];
 
             // Apply order, offset, limit and projection
@@ -292,7 +297,7 @@ class Builder extends BaseBuilder {
             if ($this->orders)  $options['sort'] = $this->orders;
             if ($this->offset)  $options['skip'] = $this->offset;
             if ($this->limit)   $options['limit'] = $this->limit;
-            if ($this->projections)   $options['projection'] = $this->projections;
+            if ($columns)   $options['projection'] = $columns;
             // if ($this->hint)    $cursor->hint($this->hint);
 
             // Fix for legacy support, converts the results to arrays instead of objects.