[Trivial] Fix warning: template.c:2899:48: warning: name lookup of ‘i’ changed [enabled by default]
    template.c:2836:16: warning:   matches this ‘i’ under ISO standard rules [enabled by default]
    template.c:2866:25: warning:   matches this ‘i’ under old rules [enabled by default]
[Trivial] Fix warning: deprecated conversion from string constant to char*
Merge pull request #2267 from yazd/warning-fixes

[Trivial] Some DMD warning fixes