Fixed missing word in error message

extension/Source/core/Constants.php

@@ -877,7 +877,7 @@ const F_FE_DATA_ERROR = 'data-error';
 
 const F_FE_DATA_PATTERN_ERROR_DEFAULT = 'pattern error'; // Attention: the default is also defined in ext_conf_template.txt
 const F_FE_DATA_REQUIRED_ERROR_DEFAULT = 'data required'; // Attention: the default is also defined in ext_conf_template.txt
-const F_FE_DATA_MATCH_ERROR_DEFAULT = 'fields do not'; // Attention: the default is also defined in ext_conf_template.txt
+const F_FE_DATA_MATCH_ERROR_DEFAULT = 'fields do not match'; // Attention: the default is also defined in ext_conf_template.txt
 
 const F_PARAMETER = 'parameter';    // valid for F_ and FE_