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

Signed-off-by: Christian Brabandt <[email protected]>

Author: zeertzjq

runtime/doc/editing.txt

@@ -1097,8 +1097,8 @@ will get the ACL info of the original file.
    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.

runtime/doc/tags

@@ -4510,7 +4510,6 @@ E1503	builtin.txt	/*E1503*
 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*