runtime(doc): remove E1507 help tag, which is no longer used (#13254)

Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/editing.txt b/runtime/doc/editing.txt
index a9c81f4..7ebb41e 100644
--- a/runtime/doc/editing.txt
+++ b/runtime/doc/editing.txt
@@ -1097,8 +1097,8 @@
    The ACL info is also used to check if a file is read-only (when opening the
 file).
 
-				*xattr* *E1506* *E1507* *E1508* *E1509*
-xattr stands for Extended Attributes  It is an advanced way to save metadata
+					*xattr* *E1506* *E1508* *E1509*
+xattr stands for Extended Attributes.  It is an advanced way to save metadata
 alongside the file in the filesystem.  It depends on the actual filesystem
 being used and Vim supports it only on a Linux system.
    Vim attempts to preserve the extended attribute info when writing a file.
diff --git a/runtime/doc/tags b/runtime/doc/tags
index f4617e8..c32b679 100644
--- a/runtime/doc/tags
+++ b/runtime/doc/tags
@@ -4510,7 +4510,6 @@
 E1504	builtin.txt	/*E1504*
 E1505	builtin.txt	/*E1505*
 E1506	editing.txt	/*E1506*
-E1507	editing.txt	/*E1507*
 E1508	editing.txt	/*E1508*
 E1509	editing.txt	/*E1509*
 E151	helphelp.txt	/*E151*