develop branch in multirun setup doesn't create `country` before referencing it

[andrewbaxter439]

This appears to be something that's been reordered (by me!!). L96 should be evaluated before L88 to avoid NullPointerException triggering the catch statement, producing error message and filling in default values:

https://github.com/centreformicrosimulation/SimPaths/blob/b10aa96b0cd4380ada716839e0fb0aed67f429de/src/main/java/simpaths/experiment/SimPathsMultiRun.java#L82-L96

Fix:

• country = Country.getCountryFromNameString(countryString); to be added before line 88
• country = Country.getCountryFromNameString(countryString); also in lower catch block as only runs once after countryString is set?