Fix incorrect version regex.

share/provers-detection-data.conf

@@ -508,7 +508,7 @@ compile_time_support = true
 exec = "coqtop -batch"
 version_switch = "-v"
 version_regexp = "The Coq Proof Assistant, version \\([^ \n]+\\)"
-version_ok = "8.4pl[1-6]"
+version_ok = "^8\.4pl[1-6]$"
 version_ok = "8.4"
 command = "%l/why3-cpulimit 0 %m -s %e -R %l/coq-tactic Why3 -R %l/coq Why3 -l %f"
 driver = "drivers/coq.drv"