Update Gentoo ebuild for Lua5.1.5

--- 1/configure 2014-06-01 15:26:29.000000000 +0400
+++ 2/configure 2014-06-01 16:26:16.951029584 +0400
@@ -4,7 +4,7 @@
os=`uname`
if [ "$os" == 'Linux' ]; then
locations=(/usr/lib /usr/lib64 /usr/lib/i386-linux-gnu /usr/lib/x86_64-linux-gnu /usr/local/lib /opt/lib)
- sonames=(liblua5.1.so.5.1 liblua5.1.so.0 liblua.so.5.1 liblua-5.1.so liblua5.1.so)
+ sonames=(liblua.so.5.1.5 liblua5.1.so.5.1 liblua5.1.so.0 liblua.so.5.1 liblua-5.1.so liblua5.1.so)
for location in "${locations[@]}" ; do
for soname in ${sonames[@]} ; do
if [ -f $location/$soname ]; then