tss.vim: guard against tss not running/no python
tss.vim: guard against tss not running/no python

clausreinke/typescript-tools,noteon/typescript-tools,robertpenner/typescript-tools,noteon/typescript-tools,i-e-b/typescript-tools,clausreinke/typescript-tools,i-e-b/typescript-tools,noteon/typescript-tools,robertpenner/typescript-tools,robertpenner/typescript-tools