CLEANUP: cfgparse: replace "realloc" with "my_realloc2" to fix to memory leak on error

my_realloc2 frees variable in case of allocation failure.

fixes #1030

realloc was introduced in 9e1758efbd68c8b1d27e17e2abe4444e110f3ebe

this might be backported to 2.2, 2.3
1 file changed