patch 9.0.0491: no good reason to build without the float feature

Problem:    No good reason to build without the float feature.
Solution:   Remove configure check for float and "#ifdef FEAT_FLOAT".
diff --git a/src/os_mac_conv.c b/src/os_mac_conv.c
index 211b235..a699ce0 100644
--- a/src/os_mac_conv.c
+++ b/src/os_mac_conv.c
@@ -585,7 +585,7 @@
 #   ifdef HAVE_LOCALE_H
 	    setlocale(LC_ALL, "");
 #   endif
-#   if defined(FEAT_FLOAT) && defined(LC_NUMERIC)
+#   if defined(LC_NUMERIC)
 	    // Make sure strtod() uses a decimal point, not a comma.
 	    setlocale(LC_NUMERIC, "C");
 #   endif