patch 9.0.0074: Coverity warns for double free

Problem:    Coverity warns for double free.
Solution:   Reset cts_text_prop_count when freeing cts_text_props.

src/charset.c

@@ -964,7 +964,10 @@ clear_chartabsize_arg(chartabsize_T *cts UNUSED)
 {
 #ifdef FEAT_PROP_POPUP
     if (cts->cts_text_prop_count > 0)
+    {
 	vim_free(cts->cts_text_props);
+	cts->cts_text_prop_count = 0;  // avoid double free
+    }
 #endif
 }
 

src/structs.h

@@ -4570,8 +4570,9 @@ typedef struct {
     char_u	*cts_line;	    // start of the line
     char_u	*cts_ptr;	    // current position in line
 #ifdef FEAT_PROP_POPUP
-    int		cts_text_prop_count;	// number of text props
-    textprop_T	*cts_text_props;	// text props (allocated) or NULL
+    int		cts_text_prop_count;	// number of text props; when zero
+					// cts_text_props is not used
+    textprop_T	*cts_text_props;	// text props (allocated)
     char	cts_has_prop_with_text; // TRUE if if a property inserts text
     int         cts_cur_text_width;     // width of current inserted text
 #endif

src/version.c

@@ -735,6 +735,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    74,
 /**/
     73,
 /**/