Increase default value length for metadata properties

The 'DEFAULT_VALUE' column in the 'UCA_METADATA.PROP' table was too
short (VARCHAR(20)), risking to truncation or errors when storing
longer default property values

Author: spannm

src/main/java/net/ucanaccess/converters/Metadata.java

@@ -29,7 +29,7 @@ public class Metadata {
             + "ORIGINAL_TYPE VARCHAR(20), COLUMN_DEF LONGVARCHAR, IS_GENERATEDCOLUMN VARCHAR(3), TABLE_ID INTEGER, UNIQUE(TABLE_ID, COLUMN_NAME) )";
 
     private static final String PROP    =
-        "CREATE MEMORY TABLE UCA_METADATA.PROP(NAME LONGVARCHAR PRIMARY KEY, MAX_LEN INTEGER, DEFAULT_VALUE VARCHAR(20), DESCRIPTION LONGVARCHAR)";
+        "CREATE MEMORY TABLE UCA_METADATA.PROP(NAME LONGVARCHAR PRIMARY KEY, MAX_LEN INTEGER, DEFAULT_VALUE VARCHAR(500), DESCRIPTION LONGVARCHAR)";
 
     /**
      * Enum of Ucanaccess driver properties.