Revert/optimize some changes from 48a2baf0e288accd206f5da5031d29076e130792
diff --git a/system/database/DB_query_builder.php b/system/database/DB_query_builder.php
index ccfd9bf..c8a1619 100644
--- a/system/database/DB_query_builder.php
+++ b/system/database/DB_query_builder.php
@@ -1535,7 +1535,7 @@
 			$this->where($where);
 		}
 
-		if ($limit !== NULL)
+		if ($limit != NULL)
 		{
 			$this->limit($limit);
 		}
@@ -1856,7 +1856,7 @@
 			$this->where($where);
 		}
 
-		if ($limit !== NULL)
+		if ($limit != NULL)
 		{
 			$this->limit($limit);
 		}
@@ -2336,4 +2336,4 @@
 }
 
 /* End of file DB_query_builder.php */
-/* Location: ./system/database/DB_query_builder.php */
+/* Location: ./system/database/DB_query_builder.php */
\ No newline at end of file