[gimp-help] Fixed typo

[Marco Ciampa <marcoc src gnome org>]

commit 8621fe12565e76287f5e072f55104ea057b5a126
Author: Marco Ciampa <ciampix posteo net>
Date:   Fri Dec 7 12:25:08 2018 +0100

    Fixed typo

 src/filters/enhance/unsharp_mask.xml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/filters/enhance/unsharp_mask.xml b/src/filters/enhance/unsharp_mask.xml
index 52c999a19..281920fa5 100644
--- a/src/filters/enhance/unsharp_mask.xml
+++ b/src/filters/enhance/unsharp_mask.xml
@@ -49,7 +49,7 @@
       phenomenon appears when printing color dots on paper.
     </para>
     <para>
-      The Sharpen filter (old name was Unsharp Mask)) sharpens edges of the
+      The Sharpen filter (old name was Unsharp Mask) sharpens edges of the
       elements without increasing noise or blemish. It is the king of the
       sharpen filters.
     </para>