uniform error message format

Author: staabm

src/Runner/CodeCoverage.php

@@ -132,7 +132,7 @@ function_exists('opcache_compile_file') &&
             ini_get('opcache.enable_cli') === '1'
         ) {
             EventFacade::emitter()->testRunnerTriggeredPhpunitWarning(
-                'Code coverage might produce unreliable results when OPCache is enabled.',
+                'Code coverage might produce unreliable results when OPCache is enabled',
             );
         }
 

tests/end-to-end/code-coverage/warn-when-opcache-enabled.phpt

@@ -37,7 +37,7 @@ Time: %s, Memory: %s MB
 
 There was 1 PHPUnit test runner warning:
 
-1) Code coverage might produce unreliable results when OPCache is enabled.
+1) Code coverage might produce unreliable results when OPCache is enabled
 
 OK, but there were issues!
 Tests: 1, Assertions: 1, PHPUnit Warnings: 1.