Minor fix to avoid crashing due to trailing ";".

Minor fix to avoid crashing due to trailing ";" in style lines. In the command line, the user sees:

$ apktool d app.apk 
I: Baksmaling...
I: Loading resource table...
Exception in thread "main" java.lang.StringIndexOutOfBoundsException: String index out of range: -80
	at java.lang.String.substring(String.java:1911)
	at brut.androlib.res.decoder.StringBlock.outputStyleTag(StringBlock.java:193)
	at brut.androlib.res.decoder.StringBlock.getHTML(StringBlock.java:170)
	at brut.androlib.res.decoder.ARSCDecoder.readValue(ARSCDecoder.java:224)
	at brut.androlib.res.decoder.ARSCDecoder.readEntry(ARSCDecoder.java:179)
	at brut.androlib.res.decoder.ARSCDecoder.readConfig(ARSCDecoder.java:167)
	at brut.androlib.res.decoder.ARSCDecoder.readType(ARSCDecoder.java:133)
	at brut.androlib.res.decoder.ARSCDecoder.readPackage(ARSCDecoder.java:108)
	at brut.androlib.res.decoder.ARSCDecoder.readTable(ARSCDecoder.java:81)
	at brut.androlib.res.decoder.ARSCDecoder.decode(ARSCDecoder.java:49)
	at brut.androlib.res.AndrolibResources.getResPackagesFromApk(AndrolibResources.java:540)
	at brut.androlib.res.AndrolibResources.loadMainPkg(AndrolibResources.java:76)
	at brut.androlib.res.AndrolibResources.getResTable(AndrolibResources.java:68)
	at brut.androlib.Androlib.getResTable(Androlib.java:51)
	at brut.androlib.ApkDecoder.getResTable(ApkDecoder.java:191)
	at brut.androlib.ApkDecoder.decode(ApkDecoder.java:116)
	at brut.apktool.Main.cmdDecode(Main.java:148)
	at brut.apktool.Main.main(Main.java:77)