Adding one more test for trailing dots

Summary: Sorry, forgot to include tests for the other side of the equation.

Test Plan: It is a test

Reviewed By: tudorb@fb.com

FB internal diff: D1455583

folly/test/FormatTest.cpp

@@ -240,6 +240,7 @@ TEST(Format, Float) {
   EXPECT_EQ("0.01", sformat("{:.2f}", 0.01));
   EXPECT_EQ("0.00", sformat("{:.2f}", 0.001));
 
+  EXPECT_EQ("100000. !== 100000", sformat("{:.} !== {:.}", 100000.0, 100000));
   EXPECT_EQ("100000.", sformat("{:.}", 100000.0));
   EXPECT_EQ("1e+6", sformat("{:.}", 1000000.0));
   EXPECT_EQ(" 100000.", sformat("{:8.}", 100000.0));