Merge pull request #2438 from Laravel-Backpack/fix-exception-collumn-…

…nullable

[4.0][BUGFIX] Define fqn for Exception.

src/app/Models/Traits/CrudTrait.php

@@ -73,7 +73,7 @@ public static function isColumnNullable($column_name)
             $conn->getDoctrineColumn($table, $column_name);
 
             return ! $conn->getDoctrineColumn($table, $column_name)->getNotnull();
-        } catch (Exception $e) {
+        } catch (\Exception $e) {
             return true;
         }
     }