concat-deps: properly recognize colon that follows target
concat-deps: properly recognize colon that follows target

Should fix cases where for weirdly formatted input files the target was
mangled erroneously.

Change-Id: I28d94a6c714b5f893ac873f84fe2022e96cf1327

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core