shell: changed dashboard icon to fa-tachometer
shell: changed dashboard icon to fa-tachometer

Closes #8173
Scribery/cockpit,Scribery/cockpit,moraleslazaro/cockpit,moraleslazaro/cockpit,petervo/cockpit,cockpituous/cockpit,cockpit-project/cockpit,deryni/cockpit,cockpituous/cockpit,deryni/cockpit,garrett/cockpit,SotolitoLabs/cockpit,deryni/cockpit,deryni/cockpit,Scribery/cockpit,martinpitt/cockpit,stefwalter/cockpit,petervo/cockpit,mvollmer/cockpit,cockpit-project/cockpit,mvollmer/cockpit,moraleslazaro/cockpit,SotolitoLabs/cockpit,Scribery/cockpit,cockpituous/cockpit,SotolitoLabs/cockpit,mareklibra/cockpit,stefwalter/cockpit,mareklibra/cockpit,Scribery/cockpit,andreasn/cockpit,SotolitoLabs/cockpit,garrett/cockpit,stefwalter/cockpit,moraleslazaro/cockpit,garrett/cockpit,martinpitt/cockpit,moraleslazaro/cockpit,mareklibra/cockpit,deryni/cockpit,mvollmer/cockpit,SotolitoLabs/cockpit,Scribery/cockpit,stefwalter/cockpit,andreasn/cockpit,cockpituous/cockpit,andreasn/cockpit,cockpit-project/cockpit,Scribery/cockpit,andreasn/cockpit,moraleslazaro/cockpit,andreasn/cockpit,martinpitt/cockpit,petervo/cockpit,stefwalter/cockpit,SotolitoLabs/cockpit,SotolitoLabs/cockpit,cockpit-project/cockpit,stefwalter/cockpit,stefwalter/cockpit,deryni/cockpit,mareklibra/cockpit,cockpituous/cockpit,deryni/cockpit,garrett/cockpit,mareklibra/cockpit,andreasn/cockpit,petervo/cockpit,petervo/cockpit,andreasn/cockpit,cockpituous/cockpit,martinpitt/cockpit,petervo/cockpit,moraleslazaro/cockpit,garrett/cockpit,mareklibra/cockpit,martinpitt/cockpit,mareklibra/cockpit,petervo/cockpit,mvollmer/cockpit,cockpit-project/cockpit,mvollmer/cockpit