MINOR: stats: get rid of the STAT_SHOWADMIN flag

This flag is used to decide to show the check box in front of a proxy
on the HTML stat page. It is always equal to STAT_ADMIN except when the
proxy has no backend capability (i.e. a pure frontend) or has no server,
in which case it's only used to avoid leaving an empty column at the
beginning of the table. Not only this is pretty useless, but it also
causes the columns not to align well when mixing multiple proxies with
or without servers.

Let's simply always use STAT_ADMIN and get rid of this flag.
diff --git a/include/types/stats.h b/include/types/stats.h
index ee16ac7..d078b67 100644
--- a/include/types/stats.h
+++ b/include/types/stats.h
@@ -34,7 +34,6 @@
 #define STAT_SHNODE     0x00000200      /* conf: show node name */
 #define STAT_SHDESC     0x00000400      /* conf: show description */
 #define STAT_SHLGNDS    0x00000800      /* conf: show legends */
-#define STAT_SHOWADMIN  0x00001000      /* conf: show the admin column */
 
 #define STAT_BOUND      0x00800000	/* bound statistics to selected proxies/types/services */
 #define STAT_STARTED    0x01000000	/* some output has occurred */
diff --git a/src/stats.c b/src/stats.c
index afa2e30..d464bd5 100644
--- a/src/stats.c
+++ b/src/stats.c
@@ -670,7 +670,7 @@
 }
 
 /* Dump all fields from <stats> into <out> using the HTML format. A column is
- * reserved for the checkbox is STAT_SHOWADMIN is set in <flags>. Some extra info
+ * reserved for the checkbox is STAT_ADMIN is set in <flags>. Some extra info
  * are provided if STAT_SHLGNDS is present in <flags>.
  */
 static int stats_dump_fields_html(struct buffer *out,
@@ -684,7 +684,7 @@
 		              /* name, queue */
 		              "<tr class=\"frontend\">");
 
-		if (flags & STAT_SHOWADMIN) {
+		if (flags & STAT_ADMIN) {
 			/* Column sub-heading for Enable or Disable server */
 			chunk_appendf(out, "<td></td>");
 		}
@@ -827,7 +827,7 @@
 	}
 	else if (stats[ST_F_TYPE].u.u32 == STATS_TYPE_SO) {
 		chunk_appendf(out, "<tr class=socket>");
-		if (flags & STAT_SHOWADMIN) {
+		if (flags & STAT_ADMIN) {
 			/* Column sub-heading for Enable or Disable server */
 			chunk_appendf(out, "<td></td>");
 		}
@@ -932,7 +932,7 @@
 			              (stats[ST_F_BCK].u.u32) ? "backup" : "active", style);
 
 
-		if (flags & STAT_SHOWADMIN)
+		if (flags & STAT_ADMIN)
 			chunk_appendf(out,
 			              "<td><input class='%s-checkbox' type=\"checkbox\" name=\"s\" value=\"%s\"></td>",
 			              field_str(stats, ST_F_PXNAME),
@@ -1188,7 +1188,7 @@
 	}
 	else if (stats[ST_F_TYPE].u.u32 == STATS_TYPE_BE) {
 		chunk_appendf(out, "<tr class=\"backend\">");
-		if (flags & STAT_SHOWADMIN) {
+		if (flags & STAT_ADMIN) {
 			/* Column sub-heading for Enable or Disable server */
 			chunk_appendf(out, "<td></td>");
 		}
@@ -1356,9 +1356,7 @@
 {
 	int ret;
 
-	if ((px->cap & PR_CAP_BE) && px->srv && (appctx->ctx.stats.flags & STAT_ADMIN))
-		flags |= STAT_SHOWADMIN;
-
+	flags |= appctx->ctx.stats.flags & STAT_ADMIN;
 	if (appctx->ctx.stats.flags & STAT_FMT_HTML)
 		ret = stats_dump_fields_html(&trash, stats, flags);
 	else if (appctx->ctx.stats.flags & STAT_FMT_TYPED)