Add missing caption on preview checkbox

lazpaint/dialog/filter/ucustomblur.lfm

@@ -66,7 +66,8 @@ object FCustomBlur: TFCustomBlur
     Left = 8
     Height = 19
     Top = 264
-    Width = 20
+    Width = 70
+    Caption = 'rsPreview'
     Checked = True
     OnChange = CheckBox_PreviewChange
     State = cbChecked

lazpaint/dialog/filter/ucustomblur.lrj

@@ -4,5 +4,6 @@
 {"hash":127421996,"name":"tfcustomblur.button_cancel.caption","sourcebytes":[114,115,67,97,110,99,101,108],"value":"rsCancel"},
 {"hash":113031038,"name":"tfcustomblur.button_loadmask.caption","sourcebytes":[76,111,97,100,32,109,97,115,107,46,46,46],"value":"Load mask..."},
 {"hash":120776574,"name":"tfcustomblur.button_editmask.caption","sourcebytes":[69,100,105,116,32,109,97,115,107,46,46,46],"value":"Edit mask..."},
+{"hash":126662215,"name":"tfcustomblur.checkbox_preview.caption","sourcebytes":[114,115,80,114,101,118,105,101,119],"value":"rsPreview"},
 {"hash":210391541,"name":"tfcustomblur.openpicturedialog1.title","sourcebytes":[79,112,101,110,32,103,114,97,121,115,99,97,108,101,32,102,105,108,101],"value":"Open grayscale file"}
 ]}