Properly fixes conversion of files with filenames containing square brackets

Unknown whether this breaks conversion of filenames containing semicolons or apostrophes

src/main/java/net/knarcraft/ffmpegconverter/converter/Converter.java

@@ -427,9 +427,9 @@ public abstract class Converter {
     static String escapeSpecialCharactersInFileName(String fileName) {
         return fileName.replace("'", "\\\\\\'")
                 .replace(",", "\\\\\\,")
-                .replace(";", "\\\\\\;");
-                /*.replace("]", "\\]") //Not sure whether these should be escaped or not
-                .replace("[", "\\[");*/
+                .replace(";", "\\\\\\;")
+                .replace("]", "\\]")
+                .replace("[", "\\[");
     }
     
     static void print(String input) throws IOException {