*: Prevented unit's Contents modification

Resolves coreos#1514

The problem was caused by the [code optimization](coreos#1376). Before that each unit was stored in its own variable. Then this code was optimized and units became stored in hash map (`getAllUnitsHashMap`). Each hash was assigned to the unit's pointer. And when template unit was checked by `requirements()` function, its content was modified by `values[i] = unitPrintf(v, *uni)` code. Once templated unit was modified, all related units (which have same hash) were modified too, because they are related to one pointer.

job/job.go

@@ -175,11 +175,14 @@ func (j *Job) requirements() map[string][]string {
 		}
 
 		if uni != nil {
+			processedValues := make([]string, len(values))
 			for i, v := range values {
-				values[i] = unitPrintf(v, *uni)
+				processedValues[i] = unitPrintf(v, *uni)
 			}
+			requirements[key] = processedValues
+		} else {
+			requirements[key] = values
 		}
-		requirements[key] = values
 	}
 
 	return requirements