add normalizeDefault() method for OCI8

Author: michalsn

system/Database/OCI8/Connection.php

@@ -349,12 +349,25 @@ protected function _fieldData(string $table): array
             $retval[$i]->max_length = $length;
 
             $retval[$i]->nullable = $query[$i]->NULLABLE === 'Y';
-            $retval[$i]->default  = rtrim($query[$i]->DATA_DEFAULT);
+            $retval[$i]->default  = $this->normalizeDefault($query[$i]->DATA_DEFAULT);
         }
 
         return $retval;
     }
 
+    /**
+     * Removes trailing whitespace from default values
+     * returned in database column metadata queries.
+     */
+    private function normalizeDefault(?string $default): ?string
+    {
+        if ($default === null) {
+            return $default;
+        }
+
+        return rtrim($default);
+    }
+
     /**
      * Returns an array of objects with index data
      *