fix typo in the new citation.

inst/CITATION

@@ -3,7 +3,7 @@ citHeader("To cite SIAMCAT in publications, please use:")
 citEntry(entry = "article",
   author = "Jakob Wirbel, Konrad Zych, Morgan Essex, Nicolai Karcher,
   Ece Kartal, Guillem Salazar, Peer Bork, Shinichi Sunagawa, Georg Zeller",
-  title = "SMicrobiome meta-analysis and cross-disease comparison enabled by
+  title = "Microbiome meta-analysis and cross-disease comparison enabled by
   the SIAMCAT machine learning toolbox",
   year = "2021",
   url = "https://doi.org/10.1186/s13059-021-02306-1",