upgrade jflex version and remove workaround

Signed-off-by: Gino Augustine <[email protected]>

Author: ginoaugustine

opengrok-indexer/pom.xml

@@ -251,7 +251,7 @@ Portions Copyright (c) 2020-2020, Lubos Kosco <[email protected]>.
             <plugin>
                 <groupId>de.jflex</groupId>
                 <artifactId>jflex-maven-plugin</artifactId>
-                <version>1.8.2</version>
+                <version>1.9.1</version>
                 <executions>
                     <execution>
                         <goals>

pom.xml

@@ -343,12 +343,6 @@ Portions Copyright (c) 2018, 2020, Chris Fraire <[email protected]>.
                             <value>bar</value>
                         </property>
                     </javaApiLinks>
-                    <sourceFileExcludes>
-                        <!-- workarounds for https://github.com/jflex-de/jflex/issues/542 -->
-                        <exclude>**/HistoryLineTokenizer.java</exclude>
-                        <exclude>**/PlainLineTokenizer.java</exclude>
-                        <exclude>**/XrefSourceTransformer.java</exclude>
-                    </sourceFileExcludes>
                 </configuration>
             </plugin>
             <plugin>