Select all occurrences does is limited to 999 lines / selections

[ddeath]

• VSCode Version: Code 1.16.1 (27492b6, 2017-09-14T16:26:20.018Z)
• OS Version: Linux x64 4.4.0-91-generic
• Extensions:

Extension	Author (truncated)	Version
vscode-mjml	att	0.0.8
vscode-eslint	dba	1.3.2
mjml-syntax	dig	0.0.1
githistory	don	0.2.3
phpcs	ika	0.7.0
cpptools	ms-	0.13.0
php-docblocker	nei	1.2.0

(1 theme extensions excluded)

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Steps to Reproduce:

1. create new file
2. add 1600 lines containing this string: 28.09.2017 09:20:34
3. select spaces at first line
4. press ctrl + shift + L
5. it select only first 999 lines instead of all of them

Reproduces without extensions: Yes

[alexdima]

Duplicate of #5887