typing a period in a triple-slash comment brings up the auto-complete UI

[chronicgamedev]

Environment data

dotnet --info output:
.NET Command Line Tools (2.1.103)

Product Information:
Version: 2.1.103
Commit SHA-1 hash: 60218cecb5

Runtime Environment:
OS Name: Windows
OS Version: 10.0.16299
OS Platform: Windows
RID: win10-x64
Base Path: C:\Program Files\dotnet\sdk\2.1.103\

Microsoft .NET Core Shared Framework Host

Version : 2.0.6
Build : 74b1c703813c8910df5b96f304b0f2b78cdf194d

VS Code version:
Version 1.23.0-insider
Commit dfeffb55b62cc2c1dde5cc1e25e98632eeb7744b
Date 2018-04-16T05:17:45.591Z
Shell 2.0.0-beta.7
Renderer 61.0.3163.100
Node 8.9.3
Architecture x64

C# Extension version:
1.14.0

Steps to reproduce

1. open a C# file
2. enter a single line comment beginning with three slashes ///
3. end the comment with a period

Expected behavior

typing a period and a space in a comment adds a period and a space

Actual behavior

typing the period opens the auto-complete UI, and pressing space will insert the first suggestion

[DustinCampbell]

This for the report! This is a duplicate of #1424.