patch 8.2.3971: build fails

Problem:    Build fails.
Solution:   Use the right error message name.
diff --git a/src/typval.c b/src/typval.c
index 0afd572..1e922dc 100644
--- a/src/typval.c
+++ b/src/typval.c
@@ -939,7 +939,7 @@
 #ifdef FEAT_FLOAT
 	    if (strict)
 	    {
-		emsg(_(e_float_as_string));
+		emsg(_(e_using_float_as_string));
 		break;
 	    }
 	    vim_snprintf((char *)buf, NUMBUFLEN, "%g", varp->vval.v_float);