Check that file exists

src/freedombone-logging

         if [ ! -d /var/log/mysql ]; then
             mkdir /var/log/mysql
         fi
-        sed -i 's|log_error =.*|log_error = /var/log/mysql/error.log|g' /etc/mysql/my.cnf
+        if [ -f /etc/mysql/my.cnf ]; then
+            sed -i 's|log_error =.*|log_error = /var/log/mysql/error.log|g' /etc/mysql/my.cnf
+        fi
     fi
     turn_on_rsys_logging
 else
         if [ -f /var/log/mysql.log ]; then
             shred -zu /var/log/mysql.log
         fi
-        sed -i 's|log_error =.*|log_error = /dev/null|g' /etc/mysql/my.cnf
+        if [ -f /etc/mysql/my.cnf ]; then
+            sed -i 's|log_error =.*|log_error = /dev/null|g' /etc/mysql/my.cnf
+        fi
     fi
     if [ -f /etc/fail2ban/fail2ban.conf ]; then
         sed -i 's|loglevel.*|loglevel = 1|g' /etc/fail2ban/fail2ban.conf