Update hint texts of all entries

The design team discussed the ellipses at the end of the hint text of
our entries and, even though they are present in most mockups, it turned
out they don't like them, so remove them.

It also turned out they don't like the prefixes like "Enter" before it,
so remove those, too.

https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/977

js/ui/shellMountOperation.js

@@ -303,7 +303,7 @@ var ShellMountPasswordDialog = GObject.registerClass({
 
             this._pimEntry = new St.PasswordEntry({
                 style_class: 'prompt-dialog-password-entry',
-                hint_text: _('Enter PIM Number…'),
+                hint_text: _('PIM Number'),
                 can_focus: true,
                 x_expand: true,
             });
@@ -323,7 +323,7 @@ var ShellMountPasswordDialog = GObject.registerClass({
 
         this._passwordEntry = new St.PasswordEntry({
             style_class: 'prompt-dialog-password-entry',
-            hint_text: _('Enter Password…'),
+            hint_text: _('Password'),
             can_focus: true,
             x_expand: true,
         });