Fix invalid value for BigDecimal in Ruby 2.4.0+

ext/oci8/ocinumber.c

@@ -1429,7 +1429,7 @@ static VALUE onum_to_d_real(OCINumber *num, OCIError *errhp)
 {
     char buf[64];
     ub4 buf_size = sizeof(buf);
-    const char *fmt = "FM9.99999999999999999999999999999999999999EEEE";
+    const char *fmt = "FM9.09999999999999999999999999999999999999EEEE";
 
     if (!cBigDecimal) {
         rb_require("bigdecimal");