Updated unique key generation to check the generated key in both tables.

Update unique key generation to check in both the tables.
" ============================================================================
" Netrw Directory Listing                                        (netrw v140)
"   /Users/vidhantmaini
"   Sorted by      name
"   Sort sequence: [\/]$,\<core\%(\.\d\+\)\=\>,\.h$,\.c$,\.cpp$,*,\.o$,\.obj$,\.info$,\.swp$,\.bak$,\~$
"   Quick Help: <F1>:help  -:go up dir  D:delete  R:rename  s:sort-by  x:exec
" ============================================================================
../
.MacOSX/
.Trash/
.config/
.netbeans-derby/
.ssh/
.vim/
Desktop/
Documents/
Downloads/
Library/
Movies/
Music/
NetBeansProjects/
Pictures/
Public/
.CFUserTextEncoding
.DS_Store
.bash_history
.gitconfig
.mysql_history
.viminfo
.Documents.swp

Signed-off-by: Vidhant Maini <vidhant_14@hotmail.com>