Remove static defaultValue (metafacture-core#415)

This was overriding every defaultValue, but maps should have the possibility
to have different default values.

Author: dr0i

metafix/src/main/java/org/metafacture/metafix/FixMethod.java

@@ -536,7 +536,7 @@ public void apply(final Metafix metafix, final Record record, final List<String>
         public void apply(final Metafix metafix, final Record record, final List<String> params, final Map<String, String> options) {
             final Map<String, String> map = getMap(metafix, record, params, options, KIND_OF_RDFMAP);
             record.transform(params.get(0), oldValue -> {
-                final String newValue = map.getOrDefault(oldValue, defaultValue);
+                final String newValue = map.getOrDefault(oldValue, map.get(Maps.DEFAULT_MAP_KEY));
                 return newValue != null ? newValue : getBoolean(options, "delete") ? null : oldValue;
             });
         }
@@ -673,7 +673,6 @@ public void apply(final Metafix metafix, final Record record, final List<String>
     private static final String ERROR_STRING_OPTION = "error_string";
 
     private static final Random RANDOM = new Random();
-    private static String defaultValue;
 
     private static Map<String, String> getMap(final Metafix metafix, final Record record, final List<String> params, final Map<String, String> options, final String kindOfMap) {
         final Map<String, String> map;
@@ -703,7 +702,6 @@ private static Map<String, String> getMap(final Metafix metafix, final Record re
             }
             map = metafix.getMap(mapName);
         }
-        defaultValue = map.get(Maps.DEFAULT_MAP_KEY); // TODO: Catmandu uses 'default'
         return map;
     }