Removed USE="svn_sources" when installing gcc-4.6.0.

This is no longer needed as we have an svn mirror in gcc.git.

BUG=none
TEST=none

Change-Id: I5fdaeb8ff4b6456128765f18c0da6f582b54a379
Reviewed-on: http://gerrit.chromium.org/gerrit/5352
Tested-by: asharif <asharif@chromium.org>
Reviewed-by: Raymes Khoury <raymes@chromium.org>
diff --git a/toolchain_utils.sh b/toolchain_utils.sh
index 2fce66b..cc3abb0 100755
--- a/toolchain_utils.sh
+++ b/toolchain_utils.sh
@@ -104,7 +104,6 @@
   USE+=" multislot"
   if echo "$atom" | grep -q "gcc-4.6.0$"
   then
-    USE+=" svn_sources"
     old_binutils_config="$(get_current_binutils_config $ctarget)"
     if [[ "$old_binutils_config" != "$ctarget-2.20.1" ]]
     then