Fix mixed spaces and hard tabs in Gerrit config

The gerrit.config template is a gitconfig-like file, so is expected
to use tab characters for indentation. Half the indented lines used
tabs already, so make the rest consistent.

Change-Id: I6e77f0278a25d688b9517c275614485518923bc9

playbooks/roles/gerrit/templates/gerrit.config.j2

@@ -54,21 +54,21 @@
 [cache]
 	directory = cache
 [cache "accounts"]
-    memoryLimit = 32768
+	memoryLimit = 32768
 [cache "accounts_byemail"]
-    memoryLimit = 32768
+	memoryLimit = 32768
 [cache "accounts_byname"]
-    memoryLimit = 32768
+	memoryLimit = 32768
 [cache "changeid_project"]
-    memoryLimit = 32768
+	memoryLimit = 32768
 [cache "groups_bysubgroup"]
-    memoryLimit = 2048
+	memoryLimit = 2048
 [cache "groups_byuuid"]
-    memoryLimit = 32768
+	memoryLimit = 32768
 [cache "permission_sort"]
-    memoryLimit = 2048
+	memoryLimit = 2048
 [cache "projects"]
-    memoryLimit = 4096
+	memoryLimit = 4096
 [cache "web_sessions"]
 	maxAge = 7days
 # Set to @openstack.org because @opendev.org lacks a valid MX
@@ -130,7 +130,7 @@
 	footer = task:
 	system = Storyboard
 [plugin "javamelody"]
-        allowTopMenu = false
+	allowTopMenu = false
 # Gerrit upstream hardcodes a .git extension for cgit.
 # The cgit settings below are the same just without the
 # .git extension.
@@ -142,40 +142,40 @@
 	type = LUCENE
 	threads = 8
 [download]
-        command = checkout
-        command = cherry_pick
-        command = pull
-        command = format_patch
-        scheme = ssh
-        scheme = anon_http
-        archive = tar
-        archive = tbz2
-        archive = tgz
-        archive = txz
+	command = checkout
+	command = cherry_pick
+	command = pull
+	command = format_patch
+	scheme = ssh
+	scheme = anon_http
+	archive = tar
+	archive = tbz2
+	archive = tgz
+	archive = txz
 # Plugin commit-message-length-validator config
 [commitmessage]
-        maxLineLength = 72
+	maxLineLength = 72
 [groups]
-        newGroupsVisibleToAll = true
+	newGroupsVisibleToAll = true
 [mimetype "image/*"]
-        safe = true
+	safe = true
 [mimetype "text/x-yaml"]
-        safe = true
+	safe = true
 [mimetype "text/xml"]
-        safe = true
+	safe = true
 [mimetype "application/xml"]
-        safe = true
+	safe = true
 [mimetype "text/x-rst"]
-        safe = true
+	safe = true
 [mimetype "text/plain"]
-        safe = true
+	safe = true
 [mimetype "text/x-puppet"]
-        safe = true
+	safe = true
 [mimetype "text/x-ini"]
-        safe = true
+	safe = true
 [mimetype "text/x-properties"]
-        safe = true
+	safe = true
 [mimetype "text/x-markdown"]
-        safe = true
+	safe = true
 [mimetype "text/css"]
-        safe = true
+	safe = true