16216 FIX Resolve Runas section in Checkmk Linux agent

Prior to this werk, the Runas section of the Checkmk agent
contained a wrong trailing slash which resulted in an error
with the find command. As a direct consequence, some or
potentially all Runas rules were inadvertently ignored, leading
to the plugin, not intended for root, being executed with root
privileges. This werk fixes this behaviour.

Change-Id: Iaa3ace9b4d1eb1c3e554826dc537d53be98ebe84

.werks/16216

@@ -0,0 +1,15 @@
+Title: Resolve Runas section in Checkmk Linux agent
+Class: fix
+Compatible: compat
+Component: checks
+Date: 1699515827
+Edition: cre
+Level: 1
+Version: 2.3.0b1
+
+Prior to this werk, the Runas section of the Checkmk agent
+contained a wrong trailing slash which resulted in an error
+with the find command. As a direct consequence, some or
+potentially all Runas rules were inadvertently ignored, leading
+to the plugin, not intended for root, being executed with root
+privileges. This werk fixes this behaviour.

agents/check_mk_agent.linux

@@ -1925,7 +1925,7 @@ run_runas_executor() {
                     echo "<<<local:sep(0)>>>"
                 fi
 
-                find "${configfile}/" -executable -type f |
+                find "${configfile}" -executable -type f |
                     while read -r filename; do
                         if [ -n "${prefix}" ]; then
                             # SC2086: We don't want to quote since prefix should not be treated as a