lua-socket-fix: fix for address resolving to localhost

it's uncertain which address bind/connect will choose when
connection to localhost. The problem is with /etc/hosts
which can contain bindings for both 127.0.0.1 and ::1 for
localhost (and some system don't).

See for futher explanation:
http://sourceware.org/bugzilla/show_bug.cgi?id=4980

test/box/socket.result

@@ -817,7 +817,7 @@ lua s:error()
 lua s:close()
 ---
 ...
-lua type(s:bind('localhost', '30303'))
+lua type(s:bind('127.0.0.1', '30303'))
 ---
  - userdata
 ...
@@ -853,7 +853,7 @@ ping
 lua s = box.socket.udp()
 ---
 ...
-lua type(s:sendto('ping', 'localhost', '30302'))
+lua type(s:sendto('ping', '127.0.0.1', '30302'))
 ---
  - number
 ...
@@ -876,7 +876,7 @@ lua s:close()
 lua s = box.socket.udp()
 ---
 ...
-lua type(s:bind('localhost', '30301'))
+lua type(s:bind('127.0.0.1', '30301'))
 ---
  - userdata
 ...

test/box/socket.test

@@ -441,12 +441,12 @@ exec admin "lua s:close()"
 # connect from test to echo server implemented in
 # stored procedure and do send/recv.
 #
-exec admin "lua type(s:bind('localhost', '30303'))"
+exec admin "lua type(s:bind('127.0.0.1', '30303'))"
 exec admin "lua type(s:listen())"
 
 s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
 s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
-s.connect(('localhost', 30303))
+s.connect(('127.0.0.1', 30303))
 s.sendall('ping')
 
 exec admin "lua client, status, addr = s:accept()"
@@ -472,7 +472,7 @@ s.bind(('localhost', 30302))
 
 # SOCK_DGRAM
 exec admin "lua s = box.socket.udp()"
-exec admin "lua type(s:sendto('ping', 'localhost', '30302'))"
+exec admin "lua type(s:sendto('ping', '127.0.0.1', '30302'))"
 exec admin "lua s:error()"
 
 data, addr = s.recvfrom(4)
@@ -490,7 +490,7 @@ exec admin "lua s:close()"
 # stored procedure and do send/recv.
 #
 exec admin "lua s = box.socket.udp()"
-exec admin "lua type(s:bind('localhost', '30301'))"
+exec admin "lua type(s:bind('127.0.0.1', '30301'))"
 exec admin "lua s:error()"
 
 s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)