icons: move mp3.png from /headers to /filetypes; align icon size

Origin commit data
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Commit: f9bcf9c785
Author: vanhofen <vanhofen@gmx.de>
Date: 2017-05-30 (Tue, 30 May 2017)

Origin message was:
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- icons: move mp3.png from /headers to /filetypes; align icon size

data/icons/filetypes/Makefile.am

@@ -4,4 +4,5 @@ install_DATA = \
 	file.png \
 	folder.png \
 	movie.png \
+	mp3.png \
 	picture.png

data/icons/headers/Makefile.am

@@ -17,7 +17,6 @@ install_DATA = \
 	language.png \
 	lcd.png \
 	mainmenue.png \
-	mp3.png \
 	multimedia.png \
 	network.png \
 	personalize.png \