fix couch_collate build with the option icu=static
diff --git a/rebar.config.script b/rebar.config.script
index fb72cdd..21bb978 100644
--- a/rebar.config.script
+++ b/rebar.config.script
@@ -58,8 +58,8 @@
         ];
 
     {_, true} ->
-        CFLAGS = GetFlag("ICU_CFLAGS", "-I.libs/icu/include"),
-        LDFLAGS = GetFlag("ICU_LDFLAGS", "-lstdc++ -fPIC " ++
+        CFLAGS = GetFlag1("ICU_CFLAGS", "-I.libs/icu/include"),
+        LDFLAGS = GetFlag1("ICU_LDFLAGS", "-lstdc++ -fPIC " ++
                                          ".libs/icu/lib/libicui18n.a " ++
                                          ".libs/icu/lib/libicuuc.a " ++
                                          ".libs/icu/lib/libicudata.a"),