Fix typo in error message
Fix typo in error message

cryos/tomviz,cryos/tomviz,cryos/tomviz,OpenChemistry/tomviz,thewtex/tomviz,cjh1/tomviz,mathturtle/tomviz,mathturtle/tomviz,OpenChemistry/tomviz,cjh1/tomviz,OpenChemistry/tomviz,cjh1/tomviz,OpenChemistry/tomviz,thewtex/tomviz,thewtex/tomviz,mathturtle/tomviz