coafile: Fix shortlog regex
coafile: Fix shortlog regex

Fixes regex which allowed commit messages with
two colons to pass and also removed redundancy
in regex.

Fixes https://github.com/coala/coala/issues/3587

karansingh1559/coala,impmihai/coala,rimacone/testing2,CruiseDevice/coala,Shade5/coala,Asalle/coala,NiklasMM/coala,coala-analyzer/coala,yashLadha/coala,aptrishu/coala,jayvdb/coala,NiklasMM/coala,shreyans800755/coala,SanketDG/coala,netman92/coala,yashtrivedi96/coala,JohnS-01/coala,coala-analyzer/coala,coala-analyzer/coala,arush0311/coala,shreyans800755/coala,SanketDG/coala,NiklasMM/coala,yashLadha/coala,nemaniarjun/coala,ayushin78/coala,Shade5/coala,arjunsinghy96/coala,jayvdb/coala,nemaniarjun/coala,arjunsinghy96/coala,sagark123/coala,coala/coala,CruiseDevice/coala,RJ722/coala,Balaji2198/coala,aptrishu/coala,coala/coala,meetmangukiya/coala,meetmangukiya/coala,MariosPanag/coala,yashtrivedi96/coala,nemaniarjun/coala,RJ722/coala,MariosPanag/coala,meetmangukiya/coala,aptrishu/coala,ayushin78/coala,Asnelchristian/coala,karansingh1559/coala,impmihai/coala,rimacone/testing2,RJ722/coala,Nosferatul/coala,Nosferatul/coala,CruiseDevice/coala,kartikeys98/coala,sagark123/coala,damngamerz/coala,sagark123/coala,incorrectusername/coala,refeed/coala,coala/coala,MariosPanag/coala,SanketDG/coala,netman92/coala,ayushin78/coala,kartikeys98/coala,Asalle/coala,arush0311/coala,yashtrivedi96/coala,Balaji2198/coala,Asnelchristian/coala,arush0311/coala,Balaji2198/coala,shreyans800755/coala,arjunsinghy96/coala,yashLadha/coala,rimacone/testing2,Shade5/coala,karansingh1559/coala,impmihai/coala,damngamerz/coala,incorrectusername/coala,Asalle/coala,incorrectusername/coala,damngamerz/coala,JohnS-01/coala,Asnelchristian/coala,JohnS-01/coala,kartikeys98/coala,netman92/coala,jayvdb/coala,refeed/coala,Nosferatul/coala,refeed/coala