fix category-clean message

The meaning of the message is:
Remove specified category from the page
(or remove page from the category),
because the page already belongs
to subcategory of specified category `child`

Change-Id: I5ea5c5b488e43564bad1b8d1061fcf2f0791c1d0
---
M category/en.json
1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/category/en.json b/category/en.json
index 207314a..190f45b 100644
--- a/category/en.json
+++ b/category/en.json
@@ -8,7 +8,7 @@
 	},
 	"category-adding": "Bot: Adding category [[:Category:%(newcat)s|%(newcat)s]]",
 	"category-also-in": "(also in %(alsocat)s)",
-	"category-clean": "Bot: Removing category %(category)s which is already in %(child)s",
+	"category-clean": "Bot: Removing category %(category)s because it's already under %(child)s",
 	"category-listifying": "Bot: Listifying from %(fromcat)s ({{PLURAL:%(num)d|1 entry|%(num)d entries}})",
 	"category-removing": "Bot: Removing from %(oldcat)s",
 	"category-renamed": "Bot: Moved from %(oldcat)s. Authors: %(authors)s",

