fixed parser extension deny list generation and usage

htroot/ConfigParser.java

@@ -61,6 +61,7 @@ public class ConfigParser {
                     }
                 }
                 env.setConfig(SwitchboardConstants.PARSER_MIME_DENY, TextParser.getDenyMime());
+                env.setConfig(SwitchboardConstants.PARSER_EXTENSIONS_DENY, TextParser.getDenyExtension());
             }
         }
 

source/net/yacy/document/TextParser.java

@@ -472,6 +472,7 @@ public final class TextParser {
     }
 
     public static void grantExtension(final String ext, final boolean grant) {
+        if (ext == null || ext.length() == 0) return;
         if (grant) denyExtensionx.remove(ext); else denyExtensionx.put(ext, v);
     }
 

source/net/yacy/search/Switchboard.java

@@ -636,6 +636,7 @@ public final class Switchboard extends serverSwitch
         // define a realtime parsable mimetype list
         this.log.logConfig("Parser: Initializing Mime Type deny list");
         TextParser.setDenyMime(getConfig(SwitchboardConstants.PARSER_MIME_DENY, ""));
+        TextParser.setDenyExtension(getConfig(SwitchboardConstants.PARSER_EXTENSIONS_DENY, ""));
 
         // prepare a solr index profile switch list
         final File solrBackupProfile = new File("defaults/solr.keys.list");