[ci skip] Fix example commands to refer to the correct versions

changelogs/unreleased/fix-install-docs.yml

+---
+title: Update minimum git version to 2.9.5
+merge_request: 16683
+author:
+type: other

doc/install/installation.md

@@ -80,7 +80,7 @@ Make sure you have the right version of Git installed
     # Install Git
     sudo apt-get install -y git-core
 
-    # Make sure Git is version 2.14.3 or higher
+    # Make sure Git is version 2.9.5 or higher
     git --version
 
 Is the system packaged Git too old? Remove it and compile from source.
@@ -93,9 +93,9 @@ Is the system packaged Git too old? Remove it and compile from source.
 
     # Download and compile from source
     cd /tmp
-    curl --remote-name --progress https://www.kernel.org/pub/software/scm/git/git-2.8.4.tar.gz
-    echo '626e319f8a24fc0866167ea5f6bf3e2f38f69d6cb2e59e150f13709ca3ebf301  git-2.8.4.tar.gz' | shasum -a256 -c - && tar -xzf git-2.8.4.tar.gz
-    cd git-2.8.4/
+    curl --remote-name --progress https://www.kernel.org/pub/software/scm/git/git-2.14.3.tar.gz
+    echo '023ffff6d3ba8a1bea779dfecc0ed0bb4ad68ab8601d14435dd8c08416f78d7f  git-2.14.3.tar.gz' | shasum -a256 -c - && tar -xzf git-2.14.3.tar.gz
+    cd git-2.14.3/
     ./configure
     make prefix=/usr/local all
 

lib/system_check/app/git_version_check.rb

@@ -5,7 +5,7 @@ module SystemCheck
       set_check_pass -> { "yes (#{self.current_version})" }
 
       def self.required_version
-        @required_version ||= Gitlab::VersionInfo.new(2, 7, 3)
+        @required_version ||= Gitlab::VersionInfo.new(2, 9, 5)
       end
 
       def self.current_version