Eliminate gpr_ int types - and insist on C99 variants instead
diff --git a/src/ruby/ext/grpc/rb_grpc.c b/src/ruby/ext/grpc/rb_grpc.c
index a752a5f..265ab58 100644
--- a/src/ruby/ext/grpc/rb_grpc.c
+++ b/src/ruby/ext/grpc/rb_grpc.c
@@ -138,7 +138,7 @@
           d += 1;
           f -= 1;
         }
-        t.tv_sec = (gpr_int64)f;
+        t.tv_sec = (int64_t)f;
         if (f != t.tv_sec) {
           rb_raise(rb_eRangeError, "%f out of Time range",
                    RFLOAT_VALUE(time));