Love Live Reader attempts to convert multiple glyphs like ITG Reader, add pre-checks

Co-authored-by: sigonasr2 <sigonasr2@gmail.com>

readers/LoveLiveReader.java

@@ -315,10 +315,14 @@ public class LoveLiveReader extends Reader{
             case 9:{
                 Font f = Font.FONT_LOVELIVE_PCT;
                 List<Glyph> glyphs = Glyph.split(cutImg);
-                glyphs.remove(glyphs.size()-3);
-                glyphs.remove(glyphs.size()-1);
-                String res = f.convertGlyphs(glyphs);
-                return res.substring(0,glyphs.size()-1)+"."+res.substring(glyphs.size()-1,glyphs.size());
+                if (glyphs.size()>3) {
+                    glyphs.remove(glyphs.size()-3);
+                    glyphs.remove(glyphs.size()-1);
+                    String res = f.convertGlyphs(glyphs);
+                    return res.substring(0,glyphs.size()-1)+"."+res.substring(glyphs.size()-1,glyphs.size());
+                } else {
+                    return "";
+                }
             }
         }
         return "";