cosmetic: Remove trailing whitespace

Change-Id: I64c8dbad3fc42bcb8dd4ac9b16bbd9c59a0cf5d5
diff --git a/configure.ac b/configure.ac
index 6e59fa2..01bec91 100644
--- a/configure.ac
+++ b/configure.ac
@@ -23,7 +23,7 @@
 	[openbsc@lists.osmocom.org])
 AC_PREREQ(2.57)
 AC_CONFIG_SRCDIR([Transceiver52M/Makefile.am])
-AC_CONFIG_AUX_DIR([.])	
+AC_CONFIG_AUX_DIR([.])
 AC_CONFIG_MACRO_DIR([config])
 AM_CONFIG_HEADER(config.h)