mysql-slave-stats.sh: always includes zeros

I forgot that pipe-to-graphite doesn't take arguments after the command
sow we can't use the --include-zeros. Let's just make it the default
cause it only adds a few metrics and missing values is annoying.

scripts/mysql-slave-stats.sh

@@ -1,21 +1,10 @@
 #!/bin/sh
 
 
-if [ "$1" == "--include-zeros" ]; then
-   # print all lines
-   awk_command='{ print }'
-else
-   # Remove all the lines where the value is 0
-   # (~50% of the 360 values were 0 when I checked)
-   awk_command='{if ($2) print}'
-fi
-
 # Produce a huge number of stats about mysql
 mysql -u root -e "show slave status \G" |
 # Skip the first line (column headers "Variable_name Value")
 tail -n +2 |
-# command from above
-awk "$awk_command" |
 # lower-case everything because Capitals_with_underscores_are_annoying
 tr '[A-Z]' '[a-z]' |
 # 1.  Remove leading spaces (from ragged-left edge) and prepend namespace.