fdo#72995: Changed label to 'Formula cell must contain a formula.'

Change-Id: Iaa8528985935549f0ef1bdc96edfbde7d9b104c9
Reviewed-on: https://gerrit.libreoffice.org/7234Reviewed-by: Kohei Yoshida <libreoffice@kohei.us>
Tested-by: Kohei Yoshida <libreoffice@kohei.us>

sc/source/ui/src/globstr.src

@@ -2047,7 +2047,7 @@ Resource RID_GLOBSTR
     };
     String STR_NOFORMULA
     {
-        Text [ en-US ] = "Cell must contain a formula." ;
+        Text [ en-US ] = "Formula cell must contain a formula." ;
     };
     String STR_INVALIDINPUT
     {